Methods of Packaging Valve Chips and Related Valve Assemblies

ABSTRACT

A valve chip may include a substrate having first and second faces and openings between the first and second faces, and a plurality of flexible valve flaps on one of the faces of the substrate with each flexible valve flap being associated with at least one of the openings. The valve chip may be packaged by forming a frame having an opening therein, and securing the valve chip in the opening of the frame. More particularly, the valve chip may be secured in the opening so that central portions of the first and second faces of the substrate are exposed through the opening in the frame and so that a fluid seal is provided between the frame and edges of the substrate. Related valves, valve assemblies, and methods are also discussed.

RELATED APPLICATIONS

This application claims the benefit of priority as a divisional of U.S.application Ser. No. 11/188,294 filed Jul. 22, 2005, which claims thebenefit of priority to U.S. Provisional Application No. 60/590,483 filedJul. 23, 2004, and to U.S. Provisional Application No. 60/590,669 filedJul. 23, 2004. The disclosures of U.S. application Ser. Nos. 11/188,294,60/590,483, and 60/590,669 are hereby incorporated herein in theirentirety by reference. This application is also related to U.S. Utilityapplication Ser. No. 11/188,139 filed Jul. 22, 2005, and entitled“Methods Of Operating Microvalve Assemblies And Related Structures andDevices”, the disclosure of which is hereby incorporated herein in itsentirety by reference.

FIELD OF THE INVENTION

The present invention relates to the field of valves, and moreparticularly to microvalves and microvalve assemblies and relatedmethods.

BACKGROUND

A conventional solenoid driven pneumatic valve may be used to control afluid flow. When electrically energized or de-energized, a solenoiddriven pneumatic valve may cut off and/or permit one or more fluidflows. An actuator of a solenoid driven pneumatic valve is anelectromagnet. When the valve is energized, a magnetic field builds upto pull and/or push a plunger against the action of a spring. Whende-energized, the plunger returns to its original position by action ofthe spring. Solenoid driven pneumatic valves are discussed, by way ofexample, in the reference “Technical Principles Of Valves” (omega.com,One Omega Drive, Stamford, Conn., 06907, J-3 to J-7), the disclosure ofwhich is hereby incorporated herein in its entirety by reference.

A flow of air (or other fluid) through a valve may be a function of anumber of controlled port connections and a number of switchingpositions. Directional valve functionalities may be described byreferring to them as a combination of “ways” and “positions”, such as,for example, a 4-way 2-position valve also referred to as a 4/2-wayvalve. The term “way” defines a number of controlled flow paths thevalve has (indicated by arrows in ISO symbology). With respect to theterm “position”, a pneumatic directional valve may have two or threeswitching positions (indicated by squares in ISO symbology).

In a conventional 5-way, 2-position solenoid driven pneumatic valve (a5/2 valve), fluid flows may be controlled between first and secondactuator ports, first and second exhaust ports, and an air supply port.When the solenoid is energized, the 5/2 valve may provide fluid couplingbetween the air supply port and the first actuator port, and between thesecond actuator port and the second exhaust port. When the solenoid isde-energized, the 5/2 valve may provide fluid coupling between the airsupply port and the second actuator port, and between the first actuatorport and the first exhaust port. A 5/2 valve may thus be used to controloperation of a pneumatic actuator coupled to the actuator ports.

A solenoid driven pneumatic valve, however, may be subject to mechanicalwear that may reduce a useful life thereof. In addition, functionalitiesprovided by a solenoid driven pneumatic valve may be limited. Moreover,a solenoid driven pneumatic valve may be unable to maintain an energizedposition in the event of a loss of power.

SUMMARY

According to some embodiments of the present invention, a valve assemblymay include a main housing defining five chambers, four valves, and acontroller. A first chamber may be coupled to a low pressure exhaustport, a second chamber may be coupled to a first actuator port, a thirdchamber may be coupled to a high pressure supply port, a fourth chambermay be coupled to a second actuator port, and a fifth chamber may becoupled to a low pressure exhaust port. Moreover, a first valve may bebetween the first and second chambers wherein the first valve allows orsubstantially blocks fluid communication between the first chamber andthe second chamber responsive to a first electrical signal; a secondvalve may be between the second and third chambers wherein the secondvalve allows or substantially blocks fluid communication between thesecond chamber and the third chamber responsive to a second electricalsignal; a third valve may be between the third and fourth chamberswherein the third valve allows or substantially blocks fluidcommunication between the third chamber to the fourth chamber responsiveto a third electrical signal; and a fourth valve may be between thefourth and fifth chambers wherein the fourth valve allows orsubstantially blocks fluid communication between the fourth chamber andthe fifth chamber responsive to a fourth electrical signal.

Moreover, the controller may be configured to generate the first,second, third, and fourth electrical signals for the respective valveassemblies, and the controller may be configured to advance the valvesthrough a sequence of conditions. In a first condition, the second andfourth valves may be opened and the first and third valves may be closedso that fluid communication is allowed between the second and thirdchambers and between the fourth and fifth chambers and so that fluidcommunication is substantially blocked between the first and secondchambers and between the third and fourth chambers. In a secondcondition after the first condition, the second valve may be opened andthe first, third, and fourth valves may be closed so that fluidcommunication is allowed between the second and third chambers and sothat fluid communication is substantially blocked between the first andsecond chambers, between the third and fourth chambers, and between thefourth and fifth chambers. In a third condition after the secondcondition, the second and third valves may be opened and the first andfourth valves may be closed so that fluid communication is allowedbetween the second and third chambers and between the third and fourthchambers and so that fluid communication is substantially blockedbetween the first and second chambers and between the fourth and fifthchambers. In a fourth condition after the third condition, the thirdvalve may be opened and the first, second, and fourth valves may beclosed so that fluid communication is allowed between the third andfourth chambers and so that fluid communication is substantially blockedbetween the first and second chambers, between the second and thirdchambers, and between the fourth and fifth chambers. In a fifthcondition after the fourth condition, the first and third valves may beopened and the second and fourth valves may be closed, so that fluidcommunication is allowed between the first and second chambers andbetween the third and fourth chambers and so that fluid communication issubstantially blocked between the second and third chambers and betweenthe fourth and fifth chambers.

According to additional embodiments of the present invention, a valveassembly may include a housing having a first chamber coupled to a lowpressure exhaust port, a second chamber coupled to a first actuatorport, a third chamber coupled to a high pressure supply port, a fourthchamber coupled to a second actuator port, and a fifth chamber coupledto a low pressure exhaust port. The valve assembly may also include afirst valve between the first and second chambers, a second valvebetween the second and third chambers, a third valve between the thirdand fourth chambers, and a fourth valve between the fourth and fifthchambers.

The second and fourth valves may be opened and the first and thirdvalves may be closed to provide a first condition so that fluidcommunication is allowed from the third chamber to the second chamberand from the fourth chamber to the fifth chamber and so that fluidcommunication is substantially blocked between the first and secondchambers and between the third and fourth chambers. After the firstcondition, the second valve may be opened and the first, third, andfourth valves may be closed to provide a second condition so that fluidcommunication is allowed from the third chamber to the second chamberand so that fluid communication is substantially blocked between thefirst and second chambers, between the third and fourth chambers, andbetween the fourth and fifth chambers. After the second condition, thesecond and third valves may be opened and the first and fourth valvesmay be closed to provide a third condition so that fluid communicationis allowed from the third chamber to the second chamber and from thethird chamber to the fourth chamber and so that fluid communication issubstantially blocked between the first and second chambers and betweenthe fourth and fifth chambers.

After the third condition, the third valve may be opened and the first,second, and fourth valves may be closed to provide a fourth condition sothat fluid communication is allowed from the third chamber to the fourthchamber and so that fluid communication is substantially blocked betweenthe first and second chambers, between the second and third chambers,and between the fourth and fifth chambers. After the fourth condition,the first and third valves may be opened and the second and fourthvalves may be closed to provide a fifth condition so that fluidcommunication is allowed from the second chamber to the first chamberand from the third chamber to the fourth chamber and so that fluidcommunication is substantially blocked between the second and thirdchambers and between the fourth and fifth chambers.

According to yet additional embodiments of the present invention, avalve may include a substrate having first and second opposing faces, aplurality of holes through the substrate between the first and secondfaces, and a pair of input pads thereon. A plurality of flexible valveflaps may be provided on the substrate with each flexible valve flapbeing associated with at least one respective hole in the substrate, andthe flexible valve flaps may be configured to open or substantiallyblock respective holes responsive to an electrical signal applied to thepair of input pads. In addition, a frame may surround and support thesubstrate at edges thereof so that central portions of the first andsecond faces of the substrate are exposed through an opening in theframe and so that a fluid seal is provided between the frame and edgesof the substrate.

According to more embodiments of the present invention, a valve chip mayinclude a substrate having first and second faces and openings betweenthe first and second faces, and a plurality of flexible valve flaps onone of the faces of the substrate with each flexible valve flap beingassociated with at least one of the openings. A frame may be formedhaving an opening therein, and the valve chip may be secured in theopening of the frame. More particularly, central portions of the firstand second faces of the substrate may be exposed through the opening inthe frame and a fluid seal may be provided between the frame and edgesof the substrate.

According to still more embodiments of the present invention, a valveassembly may include a main housing defining first, second, and thirdchambers, and defining a first valve enclosure between the first andsecond chambers and a second valve enclosure between the second andthird chambers. First, second, third, and fourth electrical housingleads may be provided in the main housing with portions of each of thefirst and second electrical housing leads being exposed in the firstvalve enclosure and with portions of the third and fourth electricalhousing leads being exposed in the second valve enclosure.

A first valve in the first valve enclosure may be electrically coupledwith the first and second electrical housing leads wherein the firstvalve is configured to allow or substantially block fluid communicationbetween the first and second chambers responsive to electrical signalsprovided on the first and second electrical housing leads. A secondvalve in the second valve enclosure may be electrically coupled with thethird and fourth electrical housing leads wherein the second valve isconfigured to allow or substantially block fluid communication betweenthe second and third chambers responsive to electrical signals providedon the third and fourth electrical housing leads. Moreover, a controllermay be electrically coupled to the first, second, third, and fourthelectrical housing leads, and the controller may be configured togenerate the electrical signals to allow or substantially block fluidcommunication between the first and second chambers and between thesecond and third chambers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an electro-statically actuated valveaccording to some embodiments of the present invention.

FIG. 2 is a plan view of a valve chip including an array ofelectro-statically actuated valves according to some embodiments of thepresent invention.

FIG. 3 is a schematic diagram of a valve assembly according to someembodiments of the present invention, depicted here controlling apneumatic actuator.

FIGS. 4A-F are schematic diagrams illustrating sequences of operationsof valve assemblies according to some embodiments of the presentinvention.

FIG. 5 is a front view of a packaging frame for a valve chip accordingto some embodiments of the present invention.

FIG. 6 is a plan view of a packaged valve chip according to someembodiments of the present invention.

FIG. 7 is a front view of a packaging frame for a valve chip accordingto some embodiments of the present invention.

FIG. 8 is a plan view of a packaged valve chip according to someembodiments of the present invention.

FIG. 9 is a plan view of electrical leads for a packaging frameaccording to some embodiments of the present invention.

FIG. 10 is an exploded view of a main housing according to someembodiments of the present invention.

FIG. 11 is a back perspective view of the main housing of FIG. 10 shownassembled according to some embodiments of the present invention.

FIG. 12 is a front perspective view of the main housing of FIG. 10 shownassembled according to some embodiments of the present invention.

FIG. 13 is a bottom perspective view of the main housing of FIG. 10according to some embodiments of the present invention.

FIG. 14 is a perspective view of an electronics sub-assembly accordingto some embodiments of the present invention.

FIG. 15 is a front perspective view of a printed circuit board of theelectronics sub-assembly of FIG. 14 according to some embodiments of thepresent invention.

FIG. 16 is a transparent view of the electronics sub-assembly of FIG. 14according to some embodiments of the present invention.

FIG. 17 is a back perspective view of a printed circuit board of theelectronics sub-assembly of FIG. 14 according to some embodiments of thepresent invention.

FIG. 18 is a perspective view of a base of a valve assembly according tosome embodiments of the present invention.

FIG. 19 is a front perspective view of a valve assembly according tosome embodiments of the present invention with encapsulation of theelectronics sub-assembly shown transparent.

FIG. 20 is a perspective view of the valve assembly of FIG. 19 accordingto some embodiments of the present invention with non-metallic portionsof the main housing excluded to show an orientation of leads of the mainhousing relative to valve chip assemblies.

FIG. 21 is a bottom perspective view of the main housing of FIG. 19 withpackaged valve chip assemblies inserted in enclosures thereof.

FIG. 22 is a back perspective view of the valve assembly of FIG. 19assembly according to some embodiments of the present invention withencapsulation of the electronics sub-assembly shown transparent.

FIG. 23 is a front view of a baffle according to some embodiments of thepresent invention.

FIGS. 24 and 25 are plan views from different sides of a packaged valvechip according to some embodiments of the present invention.

FIG. 26 is an exploded view of packaged valve chips according to someembodiments of the present invention.

FIG. 27 is a plan view of electrical leads for a packaging frameaccording to embodiments of the present invention.

FIG. 28 is an exploded view of a main housing according to someembodiments of the present invention.

FIG. 29 is a back perspective view of an assembled main housingaccording to some embodiments of the present invention.

FIG. 30 is a front perspective view of an assembled main housingaccording to some embodiments of the present invention.

FIG. 31 is a bottom perspective view of a main housing according to someembodiments of the present invention.

FIG. 32 is an enlarged cross-sectional view of an enclosure of a mainhousing and a packaged valve chip taken along portions of section lineI-I′ of FIGS. 29 and 30 according to some embodiments of the presentinvention.

FIG. 33 is a perspective view of a valve assembly according to someembodiments of the present invention with non-metallic portions of themain housing excluded to show an orientation of leads of the mainhousing relative to the valve chip assemblies.

FIG. 34 is a cross-sectional view of a valve assembly taken alongsection line I-I′ of FIGS. 29 and 30 including filters according to someembodiments of the present invention.

FIGS. 35 and 36 are perspective views of an electronics sub-assemblywith a battery cover respectively closed and open according to someembodiments of the present invention.

FIGS. 37 and 38 are top and bottom perspective views of a base for valveassemblies according to some embodiments of the present invention.

FIGS. 39 and 40 are perspective views of valve assemblies according tosome embodiments of the present invention.

FIG. 41 is a block diagram illustrating functionalities of a customcircuit such as an Application Specific Integrated Circuit (ASIC) forelectronic sub-assemblies according to some embodiments of the presentinvention.

FIG. 42 is a schematic diagram of electronic sub-assemblies including acustom circuit according to some embodiments of the present invention.

FIG. 43 is a table illustrating logic relationships between inputs andoutputs of custom circuits according to some embodiments of the presentinvention.

FIG. 44 is a table illustrating sequences for state transitions andpolarity reversals according to some embodiments of the presentinvention.

FIGS. 45A and 45B are tables illustrating pin definitions for customcircuits according to some embodiments of the present invention.

FIGS. 46A and 46B are tables illustrating design parameters for customcircuits according to some embodiments of the present invention.

FIGS. 47A and 47B are front and back perspective views of a valveassembly including a valve housing, a base, and an electronicssub-assembly according to some embodiments of the present invention.

FIG. 48 is a perspective view of a common base configured to receive aplurality of valve housings and electronics sub-assemblies according tosome embodiments of the present invention.

FIGS. 49A and 49B are schematic diagrams illustrating a valve assemblyfor vacuum applications according to some embodiments of the presentinvention.

FIGS. 50A and 50B are perspective and cross-sectional views of anintegrated pneumatic valve and cylinder assembly according toembodiments of the present invention.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art.

In the drawings, thickness and/or widths of layers, regions, and/orlines are exaggerated for clarity. It will also be understood that whenan element such as a layer, region or substrate is referred to as beingon another element, it can be directly on the other element orintervening elements may also be present. In contrast, if an elementsuch as a layer, region or substrate is referred to as being directly onanother element, then no other intervening elements are present.Similarly, an element is referred to as being “connected to” or “coupledto” another element, it can be directly connected to or coupled to theother element or intervening elements may also be present. In contrast,when an element is referred to as being directly connected to ordirectly coupled to another element, then no other intervening elementsare present. As used herein, the term and/or includes any and allcombinations of one or more of the associated listed items.

Furthermore, relative terms, such as beneath, over, under, upper, and/orlower may be used herein to describe one element's relationship toanother element as illustrated in the figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as below other elements would then be oriented above the otherelements. The exemplary term below, can therefore, encompasses both anorientation of above and below.

It will be understood that although the terms first, second, third, etc.are used herein to describe various regions, layers, sections and/orsteps, these regions, layers, sections and/or steps should not belimited by these terms. These terms are only used to distinguish oneregion, layer, section, or step from another region, layer, section, orstep. Thus, a first region, layer, section, or step discussed belowcould be termed a second region, layer, section, or step, and similarly,a second region, layer, section, or step could be termed a first region,layer, section, or step without departing from the teachings of thepresent invention. Like numbers refer to like elements throughout.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

In a pneumatic actuator, two actuator chambers are separated by apiston, and pressure differentials in the actuator chambers are used tomove the piston. A rod can be used to transfer movement of the piston toa device being actuated outside the actuator. Valve assemblies accordingto some embodiments of the present invention can be used to control airflow into and out of one or both actuator chambers of a pneumaticactuator.

Valve assemblies according to some embodiments of the present inventionmay include a plurality of arrays of valves with each array of valvesprovided on a separate substrate. Each valve may include a valveorifice(s) through a substrate and an electrostatically actuatedflexible valve flap used to gate the valve orifice(s). Moreparticularly, each flexible valve flap may be anchored to the substrateat a first end and free at all other edges. In addition, the free end ofeach flexible valve flap may curl away from the substrate so that eachflexible valve flap is normally open in the absence of an appliedelectro-static force. Valve flaps may be provided on a top surface ofthe substrate, and flow through an open valve orifice(s) may be from ahigh pressure on the bottom surface of the substrate to a low pressureon the top surface of the substrate.

The structure of an individual valve according to some embodiments ofthe present invention is illustrated in FIG. 1. As shown in FIG. 1, thevalve 100 may include a substrate 101 (such as a silicon substrate), afixed electrode 105 provided between first and second insulating layers103 and 107 on a top surface of the substrate 101, and a flexibleelectrode 111 provided between third and fourth insulating layers 109and 115. The fixed and flexible electrodes 105 and 111, for example, mayeach include a layer of a metal such as Ti, Cr, Au, Al, Cu, W, Pt,and/or other flexible conductive material such as a conductive polymer(e.g., polyanniline) and/or conductive oxide film (e.g., ITO). Whenusing certain conductive metal films (e.g., Au, Ag, Al, Cu, and/or Pt),a thin adhesion layer (e.g., Ti and/or Cr) may be provided on upperand/or lower surfaces of the conductive metal film to provide properadhesion to the insulating layers of the flexible flap. One or more ofthe insulating layers 103, 107, 109, and 115 may be layers of a polymermaterial, such as a polyimide or other photosensitive polymer. Inalternative embodiments, one of the second insulating layer 107 or thethird insulating layer 109 may be omitted, and/or the first insulatinglayer 103 may be omitted. In addition or in an alternative, insulatinglayer 107 and/or insulating layer 109 may include a ceramic dielectricsuch as silicon oxide (SiO2).

The third and fourth insulating layers 109 and 115 and the flexibleelectrode 111 define a flexible valve flap 117 adjacent a respectivevalve-orifice(s) 119 through the substrate 101. The valve hole may beformed by wet chemical etching and/or by deep reactive ion etchingthrough the substrate. The flexible valve flap 117 may be configured tocurl away from the top surface of the substrate to a normally openposition in the absence of an attractive electrostatic force between thefixed and flexible electrodes 105 and 111 to allow fluid passage from abottom surface of the substrate 101 through the valve-orifice(s) 119 andpast the flexible valve flap 117 on the top surface of the substrate101. The valve 100 may be closed by creating an attractive electrostaticforce between the fixed and flexible electrodes 105 and 111 so that theflexible valve flap 117 blocks the valve orifice(s) 119. Moreparticularly, the valve flap 117 can be made to curl to the normallyopen position away from the top of the substrate 101 by fabricating theinsulating layers 109 and 115 to have predetermined stresses therein.Microelectromechanical electrostatic valve devices are discussed, forexample, in U.S. Pat. No. 6,590,267 to Scott H. Goodwin-Johansson et(al., entitled “Microelectromechanical Flexible Membrane ElectrostaticValve Devices And Related Fabrication Methods,” the disclosure of whichis hereby incorporated herein in its entirety by reference.Electro-statically actuated valves may be provided according toembodiments of the present invention using valve flaps as discussedabove with respect to FIG. 1 or using other moveable valve members suchas micromachined diaphragms.

An array of valves 100 _(1-x,1-y) may be provided on the top surface ofa single substrate to provide the valve chip 131 shown in FIG. 2. Asshown in FIG. 2, a plurality of valves 100 _(1-x,1-y) may be arranged inrows and columns on the chip 131, with each valve 100 _(1-x,1-y)including a respective valve orifice(s) 119 (or hole(s)) and flexiblevalve flap 117 (as shown in FIG. 1). Moreover, the fixed electrodes 105of each valve 100 _(1-x,1-y) on the valve chip 131 may be electricallyconnected to each other, and the flexible electrodes 111 of each valve100 _(1-x,1-y) on the chip 131 may be electrically connected to eachother so that a voltage potential can be provided between the fixed andflexible electrodes to create an electrostatic attraction there between.While a plurality of valves (with each valve including one valve flapand one orifice) are illustrated in FIG. 2, other arrangements may beprovided for valve chips according to embodiments of the presentinvention. For example, a valve chip according to sonic embodiments ofthe present invention may include a single valve with a single valveflap and a single orifice. In an alternative, a valve chip may includeone or more valves with at least one valve including a single valve flapused to open and close a plurality of orifices.

Accordingly, the array of valves 100 _(1-x,1-y) can be opened and closedin unison. More particularly, a closing electrical potential can beapplied between the fixed electrodes 105 of the array and the flexibleelectrodes 111 of the array to create an attractive electro-static forceso that all of the flexible valve flaps 117 close all of the valveorifices 119 on the valve chip 131. Similarly, an opening electricalpotential can be applied between the fixed electrodes 105 of the arrayand the flexible electrodes 111 to remove the attractive electro-staticforce so that all of the flexible valve flaps 117 open all of the valveorifices 119 on the chip 131. By providing the array of commonlyactuated valves 100 _(1-x,1-y) on the chip 131, the valve chip 131 canregulate a greater flow of fluid than would otherwise be possible with asingle valve. Valve chips of different flow sizes (Cv) may thus beprovided with flow sizes of up to 1.0 Cv. Flow sizes, for example, inthe range of approximately 0.001 Cv to approximately 10 Cv may beprovided. (As used herein, the flow coefficient Cv is based on theimperial units system and is defined as the flow of water through avalve at 60° F. in US gallon/minute at a pressure drop of 1 lb/in².)Flow sizes may be determined, for example, by a number of valves, a sizeof valve orifices, etc. A larger valve chip may thus provide a greaterflow size. In an alternative, valves on a same chip could beindividually addressed and operated separately.

A schematic diagram of valve assemblies 141 according to someembodiments of the present invention is illustrated in FIG. 3. As shownin FIG. 3, four valve chips 131 a-d separate five chambers 143 a-e ofthe valve assembly 141. More particularly, valve chip 131 a separateschambers 143 a and 143 b; valve chip 131 b separates chambers 143 b and143 c; valve chip 131 c separates chambers 143 c and 143 d; and valvechip 131 d separates chambers 143 d and 143 e. The chambers 143 a and143 e are coupled to respective low pressure exhaust ports 142 a and 142b; the chambers 143 b and 143 d are coupled through ports 146 a and 146b to respective chambers 163 a and 163 b (separated by moveable piston165) of the pneumatic actuator 161; and the chamber 143 c is coupled toa high pressure supply port 144 c. Accordingly, the valve chip 131 a isconfigured to allow or block fluid flow from chamber 143 b to chamber143 a. The valve chip 131 b is configured to allow or block fluid flowfrom chamber 143 c to chamber 143 b. The valve chip 131 c is configuredto allow or block fluid flow from chamber 143 c to chamber 143 d. Thevalve chip 131 d is configured to allow or block fluid flow from chamber143 d to chamber 143 e.

According to some embodiments of the present invention, the valveassembly 141 and the pneumatic actuator 161 (also referred to as acylinder) may be produced separately and then coupled together. Acustomer may thus separately purchase valve assemblies and pneumaticactuators from the same or different vendors. According to otherembodiments of the present invention, the valve assembly may be embedded(or integrated) in the pneumatic actuator so that the two are producedand/or sold as one unit.

Sequential conditions of operation of the valve assembly 141 of FIG. 3are discussed in greater detail below with respect to FIGS. 4A-Faccording to some embodiments of the present invention. In one possiblestartup condition illustrated in FIG. 4A, valve flaps of all valves 100a-d on the valve chips 131 a-d are closed in a first condition atstartup. The valves are maintained closed by applying attractiveelectrostatic forces to the valve flaps of the valves. In this startupcondition, there is gauge pressure in the supply chamber 143 c only, andthere is no gauge pressure in any of the other chambers 143 a-b and 143d-e. During operations after startup, gauge pressure will be present inthe supply chamber 143 c and at least one of chambers 143 b or 143 d.The piston 165 and rod 167 are shown in the retracted position atstartup by way of example.

In a second condition of FIG. 4B, valve flaps of valves 100 b and 100 don valve chips 131 b and 131 d are opened while valve flaps on valves100 a and 100 c of valve chips 131 a and 131 c are closed. Because ofthe pressure differentials from chamber 143 c to 143 b and from chamber143 d to 143 e, valve flaps of valves 100 a and 100 c can be opened byreducing/eliminating attractive electrostatic forces applied thereto sothat the valve flaps curl to the normally open position.

Accordingly, the pressure of chambers 143 b and 163 a rises, the piston165 and rod 167 extend, and chambers 163 b and 143 d are exhaustedthrough chamber 143 e and exhaust port 142 b.

In a third condition of FIG. 4C, a sufficient equilibrium between thepressures of chambers 143 d and 143 e may be achieved so that the valveflaps of valves 100 d of valve chip 131 d can be closed, and anattractive electrostatic force on the valve flaps is used to close thevalves 100 d of valve chip 131 d. In a fourth condition of FIG. 4D,valve flaps of valves 100 c can be opened because chamber 143 d waspreviously exhausted in the condition of FIG. 4C. An electrostatic forceused to close valve flaps of valves 10 c is removed so that valves 100 care opened as valve flaps thereof curl to the normally open position asshown in FIG. 4D while the valves 100 b are maintained open. By openingvalves 100 c before the piston 165 is fully extended, an increasingpressure in chambers 143 d and 163 b may slow the piston motion.

In a fifth condition of FIG. 4E, an equilibrium can be achieved betweenchambers 143 b and 143 c and the valve flaps of valves 100 b on valvechip 131 b can be closed by applying an attractive electrostatic force.Moreover, a pressure of chamber 143 b can be increased relative to thatof chamber 143 a.

In a sixth condition of FIG. 4F after increasing a pressure of chamber143 b relative to that of chamber 143 a, the valve flaps of valves 100 aon valve chip 131 a can be opened by removing an electrostatic forceused to close the valve flaps of valves 100 a so that the valve flapscurl to the normally open position. Accordingly, the pneumatic actuatorchamber 163 a is coupled to low pressure exhaust port 142 a throughchambers 143 a and 143 b, and the pneumatic actuator chamber 163 b iscoupled to high pressure supply port 144 c through chambers 143 c and143 d. In the condition of FIG. 4F, the piston 165 and rod 167 retract.Once pressures in chambers 143 c and 143 d equalize and pressures inchambers 143 a and 143 b equalize, the valves 100 a and 100 c of valvechips 131 a and 131 c can be closed by applying attractive electrostaticforces to the valve flaps thereof and operations of FIGS. 4A-4F can berepeated to extend and retract the piston 165 and rod 167.

According to some embodiments of the present invention, the valve chips131 a-d of the valve assembly 141 may sequence through the conditions ofFIG. 4B to FIG. 4C to FIG. 4D to FIG. 4E to FIG. 4F to move the piston165 and rod 167 from an extended position to a retracted position. Thevalve chips 131 a-d of the valve assembly 141 may sequence through theconditions of FIG. 4F to FIG. 4E to FIG. 4D to FIG. 4C to FIG. 4B tomove the piston 165 and rod 167 from a retracted position to an extendedposition.

Sequencing operations discussed above with respect to FIGS. 4A-F maythus be used to extend and retract the piston 165. It will beunderstood, however, that not every command to extend the piston willresult in extension or complete extension of the piston, and that notevery command to retract the piston will result in retraction orcomplete retraction of the piston. For example, a next command may bereceived/initiated before a previous extension/retraction has beencompleted. More particularly, a next command may be received/initiatedbefore a previous extension/retraction has been completed, for example,if a fault condition is detected, if a safety sensor is tripped, and/orif a power outage is detected.

In an alternative, the valve chips of the valve assembly may sequencefrom the condition of FIG. 4F to the condition of FIG. 4D with valvechips 131 a and 131 d closed and with the valve chips 131 b and 131 copened. In another alternative, the valve chips of the valve assemblysequence from the condition of FIG. 4F to a condition with the valvechips 131 b and 131 c closed and the valve chips 131 a and 131 d opened.

Sequencing techniques discussed above with respect to FIGS. 4A-F mayincrease a maximum pressure against which the valve assembly can operateto extend and retract the actuator. Any inherent operationalrestrictions to opening the valves in an array can be reduced because ahigher pressure is present on the bottom surfaces of the valve chips.Restrictions may occur when closing a valve with a force from airpressure approximating an electrostatic closing force of the valve. Thevalves may thus be selectively opened and closed to allow reduction ofpressure differentials between adjacent chambers. By reducing pressuredifferentials between adjacent chambers, a condition can be createdwhereby valve flaps of a valve chip can be closed against asignificantly lower pressure differential than was originally present. Arelatively small delay of time (for example, on the order of about 100microseconds) may be sufficient to reduce the pressure differential whenclosing valve flaps of a valve chip in a state where a relatively highpressure differential may have otherwise been present.

Microelectromechanical valves are discussed, for example, in: U.S. Pat.No. 6,590,267 to Scott H. Goodwin-Johansson et al., entitled“Microelectromechanical Flexible Membrane Electrostatic Valve DevicesAnd Related Fabrication Methods”; U.S. Pat. No. 6,236,491 to Scott H.Goodwin-Johansson et al., entitled Micromachined Electrostatic ActuatorWith Air Gap”; and/or International Publication No. WO 02/22492. Thedisclosures of each of these patents and publications is herebyincorporated herein in its entirety by reference.

Moreover, a valve chip may be packaged using a frame according to someembodiments of the present invention as illustrated, for example, inFIGS. 5-9. Alternative embodiments of a packaged valve chip (eachincluding a valve chip 131 as discussed above with respect to FIG. 2)are illustrated in FIGS. 6 and 8. Corresponding embodiments of packagingframes without valve chips are illustrated in FIGS. 5 and 7, andembodiments of electrical leads without a frame are illustrated in FIG.9.

As shown, for example, in FIG. 5, a packaging frame 211 a according tosome embodiments of the present invention may include a body 213 a, agasket 215 a, and electrical leads 217. The frame 211 a has a window 219a therein and a recessed ledge 221 a surrounding the window 219 a. Inaddition, a trough 223 a may surround the ledge 221 a. A combined widthof the ledge 221 a and trough 223 a may be in the range of approximately0.025 inches to approximately 0.060 inches. More particularly, acombined width of the ledge 221 a and trough 223 a may be in the rangeof approximately 0.050 inches to approximately 0.060 inches. Theelectrical leads 217 may be formed of stamped metal, and the electricalleads 217 may be plated with tin (approximately 150 micro inches) andthen plated with gold (approximately 40 micro-inches). The body 213 amay be formed of injection molded insulating material (such as a plasticmaterial, an elastomeric material, a polymer, a co-polymer, and/orderivatives thereof), and the gasket 215 a may be formed of an injectionmolded flexible sealing material such as rubber, viton, and/or silicone.The gasket 215 a may provide a static fluid seal with respect to a mainhousing of a valve assembly.

More particularly, the body 213 a may be formed by injection moldinginsulating material (such as a plastic material, an elastomericmaterial, a polymer, a co-polymer, and/or derivatives thereof) with theelectrical leads 217 being provided as inserts in the mold. Moreover,the gasket 215 a may be formed together with the body 213 a using atwo-shot molding process and/or an overmolding process. The ledge 221 amay be recessed relative to a surrounding portion of the body 213 a sothat a valve chip can be supported at edges thereof on one side by theledge with top and bottom surfaces of the valve chip exposed for fluidcommunication therethrough. In addition, the ledge 221 a may besufficiently recessed so that a subsequently placed valve chip is alsorecessed within the body 213 a. Moreover, portions of the electricalleads 217 are exposed adjacent the window 219 a for electricalconnection (such as by wire bonding, solder bumping, conductive epoxy,or other means known to those having skill in the art) to a subsequentlyplaced valve chip. In addition, notches 225 a in the body 213 a may beprovided adjacent portions of the ledge 221 a to allow room for a toolto place a valve chip on the ledge with other portions of the body 213 afitting more closely to the valve chip. Portions of the body 213 asurrounding the leads 217 may be angled (for example, at approximately30 degrees) to provide wire bonding tip clearance. While injectionmolding is discussed herein by way of example, other molding techniquessuch as insert molding and/or blow molding may be used.

An adhesive can then be provided in the trough 223 a, and a valve chip131 can be placed on the ledge 221 a, with the trough 223 a providingfor placement, retention, and/or control of spreading of the adhesiveuntil it is fully cured. More particularly, an adhesive bead having awidth of approximately 0.015 inches may be used. The valve chip may beplaced on the ledge 221 a with accuracy of approximately 0.005 inchesusing optical sensor equipment. Accordingly, indication marks may bemolded into the body 213 a of the packaging frame. More particularly,indication marks may be molded to include perpendicular intersectinglines having an appearance similar to that of an “L”, a “T”, a “+”, orother similar characters. Moreover, the indication marks may have adepth of approximately 0.010 inches.

An adhesive used to secure the valve chip 131 on the ledge 221 a may becured at approximately 150 degrees C. (302 degrees F.) for approximately1 hour. In an alternative, the adhesive may be cured for a longer the ata lower temperature. Polycarbonate, for example, may be used for thebody 213 a and polycarbonate may have a melting temperature in the rangeof approximately 430 degrees F. to approximately 480 degrees F. Toreduce deformation of the body 213 a, however, adhesive curetemperatures may be maintained in the range of approximately 125 degreesF. to approximately 200 degrees F. In an alternative, a UV cured epoxymay be used as an adhesive.

Portions 229 of the body 213 a may be deformed around the exposed edgesof the valve chip 131 to provide the structure illustrated in FIG. 6.The adhesive may provide a fluid seal between the valve chip 131 and thebody 213 a, and the deformed portions 229 may secure the valve chipwithin the body 213 a. More particularly, portions 229 of the body 213 amay be deformed using a heated tool (such as a heat stake) to retain thevalve chip 131 within the body 213 a. Accordingly, edges of the valvechip 131 may be supported on one side by the ledge 221 a and on theother side by the deformed portions 229 of the body 213 a. Moreover, asurface of the valve chip 131 adjacent the leads 217 may be recessedapproximately 0.010 inches relative to the leads 217 and approximately0.030 inches relative to a surface of the body 213 a surrounding thenotches 225 a, ledge 221 a, and trough 223 a.

On the valve chip 131 all fixed electrodes may be electrically connectedto a first input pad (such as a first gold bond pad), and all flexibleelectrodes may be electrically connected to a second input pad (such asa second gold bond pad), and the input pads may be electricallyconnected (e.g., via wire bonding such as gold wire bonding, solderbumping, conductive epoxy, or other means known to those having skill inthe art) to exposed portions of respective electrical leads 217 adjacentthe window 219 a. A glob-top potting 231 a can be used to protect theelectrical connection between the input pads of the valve chip 131 andthe electrical leads 217. Portions of the electrical leads 217 areexposed on an edge of the body 213 for electrical coupling to a mainhousing of a valve assembly.

According to alternate embodiments shown, for example, in FIG. 7, apackaging frame 211 b according to some embodiments of the presentinvention may include a body 213 b, a housing gasket 215 b, andelectrical leads 217. The frame 211 b has a window 219 b (also referredto as a through hole) therein and a recessed ledge 221 b surrounding thewindow 219 b. In addition, a chip gasket 216 b may be provided on theledge 221 b.

A width of the ledge 221 b may be in the range of approximately 0.025inches to approximately 0.060 inches. More particularly, a width of theledge 221 b may be in the range of approximately 0.050 inches toapproximately 0.060 inches. The electrical leads 217 may be formed ofstamped metal, and the electrical leads 217 may be plated with tin(approximately 150 micro inches) and then plated with gold(approximately 40 micro-inches). The body 213 b may be formed ofinjection molded insulating material (such as a plastic material, anelastomeric material, a polymer, a co-polymer, and/or derivativesthereof), and the gaskets 215 b and 216 b may be formed of an injectionmolded flexible sealing material such as rubber, viton, and/or silicone.The gasket 215 b may provide a static fluid seal with respect to a mainhousing. The gasket 216 b may provide a static fluid seal with respectto a valve chip placed thereon.

More particularly, the body 213 b may be formed by injection moldinginsulating material (such as a plastic material, an elastomericmaterial, a polymer, a co-polymer, and/or derivatives thereof) with theelectrical leads 217 being provided as inserts in the mold. Moreover,the gaskets 215 b and 216 b may be formed together with the body 213 busing a two-shot molding process and/or an overmolding process. Theledge 221 b may be recessed relative to a surrounding portion of thebody 213 b so that a valve chip can be supported at edges thereof on oneside by the ledge 221 b and the gasket 216 b with top and bottomsurfaces of the valve chip exposed for fluid communication therethrough.In addition, the ledge 221 b may be sufficiently recessed so that asubsequently placed valve chip is also recessed within the body 213 b.Moreover, portions of the electrical leads 217 are exposed adjacent thewindow 219 b for electrical connection (such as by wire bonding, solderbumping, conductive epoxy, or other means known to those having skill inthe art) to a subsequently placed valve chip. In addition, notches 225 bin the body 213 b may be provided adjacent portions of the ledge 221 bto allow room for a tool to place a valve chip on the ledge with otherportions of the body 213 b fitting more closely to the valve chip.Portions of the body 213 b surrounding the leads 217 may be angled (forexample, at approximately 30 degrees) to provide wire bonding tipclearance.

A valve chip 131 can be placed on the gasket 216 b, with the gasket 216b providing a static fluid seal with respect to a valve chip placedthereon. In an alternative to the gasket 216 b or in addition, a stampedadhesive tape may be used to secure the valve chip to the ledge. Thevalve chip may be placed on the gasket 216 b with accuracy ofapproximately 0.005 inches using optical sensor equipment. Accordingly,indication marks may be molded into the body 213 b of the packagingframe. More particularly, indication marks may be molded to includeperpendicular intersecting lines having an appearance similar to that ofan “L”, a “T”, a “+”, or other similar character. Moreover, theindication marks may have a depth of approximately 0.010 inches.

Portions 229 of the body 213 b may be deformed around the exposed edgesof the valve chip 131 to provide the structure illustrated in FIG. 8.The deformed portions 229 may secure the valve chip against the gasket216 b within the body 213 b. More particularly, portions 229 of the body213 b may be deformed using a heated tool (such as a heat stake) toretain the valve chip 131 within the body 213 b. Accordingly, edges ofthe valve chip 131 may be supported on one side by the ledge 221 b andgasket 216 b and on the other side by the deformed portions 229 of thebody 213 b. Moreover, a surface of the valve chip 131 adjacent the leads217 may be recessed approximately 0.010 inches relative to the leads 217and approximately 0.030 inches relative to a surface of the body 213 bsurrounding the notches 225 b and ledge 221 b.

Moreover, the valve chip 131 may be packaged before releasing the valveflaps 117. More particularly, the valve flaps 117 may be formed on asacrificial oxide, and the sacrificial oxide may be maintained while thevalve chip 131 is being assembled in the packaging frame. Thesacrificial oxide may then be removed using a dry (vapor) HF(hydrofluoric acid) release without significantly damaging the packagingframe. More particularly, the packaging frame may be formed of vitonand/or other materials which may be resistant to damage from a dry(vapor) HF release. While sacrificial oxide layers are discussed by wayof example, other sacrificial layers (such as sacrificial metal layers)may be used with other suitable vapor and/or wet chemical etchants.

In an alternative, valve flaps of a valve chip may be released byremoving sacrificial oxide using a wet HF acid etch either before dicingfrom a wafer including a plurality of valve chips, after dicing butbefore packaging, or after packaging. More particularly, the sacrificialoxide layer may be removed from the valve chip using a 49% HF solutionfor approximately 10 minutes, and the wet etch may be followed by ade-ionized (DI) water rinse, an isopropyl alcohol rinse, and first andsecond methanol rinses for 20 minutes each to remove any residual HFand/or water. After the wet processing, the valve chip with the releasedvalve flaps may be primed with methanol for a supercritical dry cycle toreduce any surface tension that may otherwise result in stiction betweenvalve flaps and the substrate.

More particularly, the valve chip may be loaded into a dryer chamber andcovered with methanol, and liquid CO) is then used to displace themethanol from the chamber at a pressure of approximately 1200 psig. Onceall of the methanol is displaced, the chamber is heated past thesupercritical point (approximately 31 degrees C.) to transition the CO₂from the liquid to gas phase, and the pressure is released to vent thesystem of CO₂ vapor. Because supercritical CO₂ has extremely low surfacetension, CO₂ is less likely to pull the valve flaps down as ittransitions from liquid to gas. Commercially available and/or customsupercritical dryers may be used.

Visual inspection can be used to determine that an acceptable number ofthe valve flaps on a valve chip are successfully released. Inparticular, a surface of the valve chip has a different color thanexposed silicon under the flappers which is visible when the valve flapsare released and the valve chip is unpowered, and the color variationscould be inspected. In an alternative, light can be projected throughthe wafer after release, and an optical detector could detect lightdifferences between the powered (closed) and unpowered (open) valvechip. In either example, machine vision systems could be used to performthe inspections.

On the valve chip 131 all fixed electrodes may be electrically connectedto a first input pad (such as a first gold bond pad), and all flexibleelectrodes may be electrically connected to a second input pad (such asa second gold bond pad), and the input pads may be electricallyconnected to exposed portions of respective electrical leads 217adjacent the window 219 b, for example, using wire bonding such as goldwire bonding, solder bumping, conductive epoxy, or other means known tothose having skill in the art. A glob-top potting 231 b can be used toprotect the electrical connections between the input pads of the valvechip 131 and the electrical leads 217. Portions of the electrical leads217 are exposed on an edge of the body 213 b for electrical coupling toa main housing.

Moreover, tooling used to mold packaging frames according to someembodiments of the present invention illustrated in FIGS. 5-8 may beadaptable so that packaging frames with the same outer dimensions aremolded with different window dimensions using substantially the samemold tooling. For example, a same mold base could be used to formdifferent packaging frames with different mold lids being used toprovide different window sizes, shapes, and/or locations. Accordingly,packaging frames may be efficiently fabricated for valve chips ofdifferent sizes. More particularly, a smaller window may be provided fora smaller valve chip for an application requiring a lower fluid flowcapacity, and the smaller window may be provided adjacent the electricalleads (instead of being centered) to provide proximity for wire bonding.By providing the packaging frames with the same outer dimensions fordifferent valve chip sizes, a same main housing may receive packagedvalve chips of different capacities/sizes to provide different operatingcharacteristics.

In addition, a baffle may be provided on the body (213 a or 213 b) ofthe frame (211 a or 211 b) to deflect pressure spikes and/or reducestress on the electrostatic valve flaps of the valve chip 131. Moreparticularly, the baffle may be provided on the body (213 a or 213 b)within the gasket (215 a or 215 b) adjacent the side of the valve chip131 including the flexible valve flaps and input pads. Moreover, thebaffle may be provided as a plate that is secured to the body (213 a or213 b) with an adhesive.

An example of a baffle 971 is illustrated in FIG. 23. As shown, thebaffle 971 includes an orifice 973 there through, and dimensions of thebaffle 971 may be such that the baffle is slightly longer and wider thanthe valve chip 131 but slightly less than interior dimensions of thegasket (215 a or 215 b). Accordingly, the baffle 971 may be securedadjacent and spaced apart from the valve chip 131 and within the gasket(215 a or 215 b). Moreover, a recess may be provided in the body (213 aor 213 b) of the frame in which the baffle 971 can be placed, and therecess may define a spacing between the baffle 971 and the valve chip131. Moreover, the baffle 971 may be placed such that the orifice 973 isadjacent a portion of the valve chip 131 most distant from theelectrical leads 217. By including the baffle 971, valve flaps of thevalve chip 131 may be protected during handling and subsequent assembly.In addition, the baffle 971 may provide a more laminar flow though thevalve chip 131, and/or increase the speed of sequencing a valve assemblyincluding packaged valve chips with the baffle. In an alternative, useof the baffle may eliminate the need for sequencing. While the baffle971 is illustrated with a single elongate orifice, different shapes,configurations, and/or orientations may be provided, and/or a pluralityof orifices may be provided.

The use of a baffle may provide a baffle chamber between the baffle andthe associated valve chip with the valve flaps of the valve chipphysically protected in the baffle chamber during handling and/orassembly. Moreover, an orifice(s) in the baffle may sufficientlyrestrict fluid flow so that a maximum force applied to the valve flapsof the valve chip may be reduced. In addition, a volume of the bafflechamber may be sufficiently small relative to the associated chamber ofthe valve housing so that a laminar fluid flow through the valve chipcan be attained more quickly and so that fatigue of the valve flaps canbe reduced. Baffles and sequencing operations (as discussed with respectto FIGS. 4A-F) can thus be used separately or in combination to increasepressures against which the valve chips can operate, to reduce fatigue,to improve flows, etc.

Moreover, baffles with orifices of different sizes may be provided fordifferent valve chips in a same valve assembly. A 5-way valve, forexample, with baffles providing greater flows into actuator ports andmore restricted flows out of actuator ports may provide relativelysmooth piston motion and maximum piston velocities may be reduced.

The packaged valve chips can be plugged in and out of a main housing asdiscussed in greater detail with respect to FIGS. 13 and 21.Accordingly, a valve assembly including one or more packaged valve chipsmay be repairable and/or adaptable. A valve assembly with amalfunctioning valve chip may thus be repaired by removing the packagedvalve chip that is not working and inserting a new packaged valve chip.In addition, functionality of a valve assembly may be changed byreplacing original packaged valve chips with new packaged valve chipshaving a different characteristic (such as different flow capacityand/or size of valve chip).

A main housing according to some embodiments of the present invention isillustrated in FIGS. 10-13. More particularly, an exploded view of amain housing 401 and associated components is illustrated in FIG. 10,and a bottom perspective view of the main housing is illustrated in FIG.13. As shown in the bottom view of FIG. 13, the main housing 401 definesthe valve assembly chambers 143 a-e discussed above with respect toFIGS. 3 and 4A-F. The main housing 401 also includes enclosures 403 a-dconfigured to receive packaged valve chips (such as discussed above withrespect to FIGS. 6 and 8) perpendicular to a length of the main housing.In addition, main housing 401 includes conductive leads 405 therein usedto transmit signals to metal leads 217 of the packaged valve chips inenclosures 403 a-d. In addition, a base gasket 407 may be included toprovide a fluid seal with respect to a base of the assembly (illustratedin FIG. 18), and a PCB gasket 409 may be included to provide a seal foran external connection to the leads 405 of the main housing.

The main housing 401 may be formed by injection molding an insulatingmaterial (such as a plastic material, an elastomeric material, apolymer, a co-polymer, and/or derivatives thereof) with conductive leads405 insert molded therein, and the gaskets 407 and/or 409 may be formedof a flexible sealing material using a two-shot molding process and/oran overmolding process. More particularly, the molding tool creates thefive separate chambers 143 a-e for high pressure air supply and lowpressure exhaust as discussed above with respect to FIGS. 3 and 4A-F.When injection molding the main housing, a hole 411 may be included inthe outside of the housing to accommodate formation of interior holesbetween chambers 143 a-e. The hole 411 in the outside of the housing maybe sealed with a plug 413 that may be glued, welded or otherwise affixedto seal the hole 411. In addition, baffles may be provided adjacentvalve chips to deflect pressure spikes and/or reduce stress on theelectrostatic valve flaps. Baffles, for example, may be provided asplates in the main housing 401 adjacent low pressure sides of the valvechips 131. As discussed above, baffles may be provided on packagingframes used to package the valve chips before insertion into the mainhousing. Baffles may provide a more laminar flow though the valve chips,a speed of sequencing a valve assembly including baffles may beincreased, and/or baffles may eliminate a need for sequencing.

The main housing 401 may also have banjo fittings 415 a-b, O-rings 417a-b, and collets 419 a-b (also referred to as quick connect fittingsand/or cartridges) affixed thereto. More particularly, the collets 419a-b may be push-in style cartridges. More particularly, the banjofittings 415 a-b may be affixed to the main housing 401, for example,using ultrasonic welding and/or an adhesive, and the banjo fittings 415a-b are in fluid communication with the chambers 143 b and 143 d of thevalve assembly. The O-rings 417 a-b and the collets 419 a-b may then beinserted in the banjo fittings 415 a-b for retention of air-tubesproviding fluid communication with the pneumatic actuator chambers 163a-b (shown in FIG. 3). The main housing 401 can be used to provideeither a three-way valve or a five-way valve depending on the number ofpackaged devices used and locations thereof to control fluid flow byplacing the plug 413 at either the outermost edge of the fifth chamber(5-way) or between the third and fourth chambers (3-way).

As discussed above, a microelectromechanical systems (MEMS) valve chip131 may be packaged in a frame to provide a packaged valve chip asillustrated, for example, in FIGS. 6 and/or 8. Packaged valve chips maybe plugged in and out of respective enclosures 403 a-d of the mainhousing 401 so that the valve assembly is adaptable and/or repairable.The gasket 215 a or 215 b of the packaged valve chip provides a fluidseal with the respective enclosure 403 a-d so that fluid communicationbetween enclosures is only provided through openings in respective valvechips. Moreover, the valve chip 131 in a packaged valve chip isdirectional and the gasket 215 a or 215 b should mate with apredetermined side of the particular enclosure so that the packagedvalve chip is oriented in the main housing 401 to provide the fluidflows between chambers 143 a-e discussed above with respect to FIGS.4A-F.

In some embodiments of the present invention, it may be desirable toprovide different fluid flows through different flow paths of the valveassembly. For example, different enclosures 403 a-d of the main housing401 may be populated with packaged valve chips providing different flowcharacteristics. More particularly, some of the enclosures 403 a-d maybe populated with packaged valve chips with relatively fewer and/orsmaller valve orifices (holes), others of the enclosures may bepopulated with packaged valve chips with relatively more and/or largervalve orifices (holes), and all of the packaged valve chips may have thesame exterior dimensions. In addition, packaged valve chips withrelatively fewer and/or smaller valve orifices (holes) may be providedwith baffles having relatively fewer and/or smaller baffle orifices(holes), and packaged valve chips with relatively more and/or largerorifices (holes) may be provided with baffles having relatively moreand/or larger baffle orifices (holes). In an alternative, differentflows may be provided by different packaged valve chips having the samenumber and sizes of valve orifices (holes) by providing baffles havingdifferent numbers and/or sizes of baffle orifices (holes).

As discussed above, an interior dimension of a window of a frame used topackage a valve chip can be varied to accommodate valve chips ofdifferent sizes without varying outer dimensions of the packaged valvechip assembly. A same main housing 401 may thus receive packaged valvechip assemblies in enclosures 403 a-d having different flow capacitycharacteristics. Stated in other words, the size of a MEMS valve chipmay be varied to provide different flow characteristics (for example, inthe range of approximately 0.001 Cv to approximately 10 Cv) whilemaintaining a same envelope geometry of the packaged valve chip.

In addition, exposed portions of the metal leads 217 on an edge of thepackaged valve may mate with corresponding leads of the main housing 401to provide communication of electrical signals from outside the mainhousing with fixed and flexible electrodes of the valve chips pluggedinto enclosures 403 a-d of the main housing 401.

While not shown in FIGS. 10-13, filters may be provided in one or moreof the chambers 143 a-e to protect the microvalves. For example, afilter in chamber 143 c may protect microvalves from particles and/orother debris from a high pressure supply, and filters in chambers 143 band 143 d may protect microvalves from particles and/or other debrisintroduced from the actuator during the exhaust cycle.

An electronics sub-assembly 501 for valve assemblies according to someembodiments of the present invention is illustrated in FIGS. 14-17. Moreparticularly, a printed circuit board 503 may include electroniccircuitry and/or software and/or firmware used to control operations ofthe valve chips 131 included in the main housing 401. For example, theprinted circuit board 503 may include electronic circuitry and/orsoftware to control and/or drive the valve chips 131 in accordance withoperations discussed above with respect to FIGS. 4A-F as instructed by aremote device such as a programmable logic controller (PLC).

The printed circuit board may include integrated circuit chips 505,resistors, capacitors, and/or inductors thereon. In addition, leads 507on the printed circuit board 503 may provide electrical coupling withleads of the main housing 401, and one or more connectors 509 (such asMolex connectors) may provide electrical connection to a remotecontroller such as a PLC. The printed circuit board may be configured toprovide a plurality of different operating characteristics with oneparticular programming characteristic being selected using jumpers 511or other means such as a dip switch(es), shunt(s) 510, etc. Moreparticularly, the printed circuit board may include one or more customcircuits (for example, including application specific integrated circuitASIC devices) as discussed below with respect to FIGS. 41-44, 45A-B, and46A-B. Additional operations of valve assemblies and/or electronicsub-assemblies thereof are discussed in the U.S. Provisional ApplicationNo. 60/590,699 to Kevin Douglas et al., entitled “Methods Of OperatingElectrostatically Actuated Microvalve Assemblies And Related Structures”and filed Jul. 23, 2004 (hereinafter “Douglas et al.”). The disclosureof this provisional application is hereby incorporated herein in itsentirety by reference.

During normal operation, the printed circuit board 503 may receiveoperating power along with control signals through connector(s) 509. Analternate power source such as a battery 513 may also be provided sothat the printed circuit board can sequence the valve chips 131 to apredetermined default condition in the event of a power outage. While abattery is shown in FIG. 15, other alternate power sources (such as acapacitive storage device and/or a fuel cell) could be used. The printedcircuit board 503 may also include a high voltage drive circuit (such asa multiple stage charge pump) used to drive the valve chip electrodes.For example, a 24V external power supply may be provided through theconnector 509, and a high voltage drive circuit may generate a 150Voutput used to drive the valve chip electrodes through leads 507, leads405, and leads 217. The printed circuit board may also include atransient voltage suppression (TVS) device 517 (such as a pair ofserially connected and opposing zener diodes).

A controller of the electronic sub-assembly may be configured to monitorthe external power supply, and upon detecting interruption of theexternal power supply, to advance the valve chips 131 a-d to apredetermined default condition and to hold that default condition usingenergy provided from the alternate power source. Upon detectinginterruption of the external power supply, for example, the currentcondition of the valve chips 131 a-d may be maintained. In analternative, upon detecting interruption of the external power supply,the controller may close the valve chips 131 a-d so that fluidcommunication is blocked between each of the chambers 143 a-e. Inanother alternative, upon detecting interruption of the external powersupply, the controller may close valve chips 131 b-c and open valvechips 131 a and 131 d. In still another alternative, upon detectinginterruption of the external power supply, the controller may closevalve chips 131 a and 131 d and open valve chips 131 b-c.

The electronics sub-assembly 501 including the printed circuit board 503and the battery 513 may be encapsulated in an insulating material (suchas a plastic material, an elastomeric material, a polymer, a co-polymer,and/or derivatives thereof) as illustrated in FIGS. 14 and 16, forexample, using an over-molding process. More particularly, an epoxy maybe used that can be cured at a relatively low temperature and pressureto protect the electronics therein. An external geometry of theencapsulated electronics sub-assembly may be provided that fits on themain housing 401 so that the leads 507 of the printed circuit board 503mate with the leads 405 of the main housing 401.

In an alternative, a battery or other electrical power storage devicemay be removable from the electronics sub-assembly and/or a battery maybe provided outside the encapsulation of the electronics sub-assembly.Accordingly, the battery may be more easily replaced. For example, abattery may be provided in a cable used to supply power and/or controlsignals to the electronics sub-assembly. Moreover, the electronicssub-assembly may include circuitry configured to charge the batteryduring normal operations using externally provided power. Accordingly, alife of a battery may be extended.

A base 601 for valve assemblies according to some embodiments of thepresent invention is illustrated in FIG. 18. The base 601 may be formedusing a metal casting process. More particularly, the base 601 may beformed of a metal such as aluminum or stainless steel, and the exhaustports 142 a-b and the supply port 144 c may be threaded tapped holes.Additional screw tapped holes 603 a-b may be used to secure the mainhousing 401 onto the base 601. In addition, clearance and/or mountingholes 605 (perpendicular to and/or parallel with the ports) may beprovided in the base for mounting the valve assembly.

By using a cast metal as the base, an integrity of the threads in theholes may be more easily maintained. Moreover, an epoxy finish may beprovided on a cast aluminum base for protection and/or aestheticpurposes. In an alternative, the base 601 may be formed from aninjection molded material (such as a plastic material, an elastomericmaterial, a polymer, a co-polymer, and/or derivatives thereof) usingmetallic inserts at threaded locations.

The valve assembly may be completed by plugging packaged valve chips(such as illustrated in FIGS. 6 and 8) into enclosures in the bottom ofthe main housing 401 (as shown in FIG. 21); securing the main housing(including the packaged valve chips therein) to the base 601 usingscrews 701; and plugging the electronics sub-assembly onto the mainhousing as shown in FIGS. 19 and 21-22. FIG. 20 illustrates the valveassembly with non-metallic portions of the main housing not shown sothat leads of the main housing are visible, and so that interconnectionsof leads 217, 405, and 507 are visible.

The same main housing, base, and electronics sub-assembly can beconfigured for either 5-way or 3-way valve operations. For 5-wayoperations, as discussed above with respect to FIGS. 4A-F, four packagedvalve chips may be plugged into respective enclosures in the bottom ofthe main housing as shown, for example, in FIG. 21. For 3-way valveoperations, a packaged valve chip may be plugged into each of the twoenclosures most distant from the electronics sub-assembly, and a sealingplug 413 may be plugged into the two enclosures closest to theelectronics sub-assembly so that chambers 143 d-e are permanentlysealed. As discussed above, a same electronics sub-assembly may beconfigured to provide one of a plurality of modes of operation definedin memory (such as ROM, PROM, EPROM, EEPROM, etc.) depending on aselection made using a jumper(s), a switch(es), a shunt(s), a fuse(s),or other selection device that can be set during and/or aftermanufacture. For example, a same electronics sub-assembly can be used tocontrol either 5-way, 4-way, 3-way, or 2-way operations depending on aswitch, shunt, fuse, and/or jumper setting. For example, 3-way and 5-wayvalve operations are discussed in Douglas et al.

In further alternatives, a main housing, base, and electronicssub-assembly can be configured for 4-way and/or 2-way valve operations.For 4-way operations, the base may be modified so that fluid coupling isprovided between exhaust chambers 143 a and 143 e and a same exhaustport. Otherwise, 4-way operations may be provided with four valve chipsas discussed above with respect to FIGS. 4A-F. In an alternative, 2-wayoperations may be provided using a single valve chip to provide aunidirectional on/off flow device. A 2-way device could be providedusing the components of FIGS. 10-13 with one valve chip and plugssubstituted for other valve chips. In an alternative, a 2-way devicecould be provided using a smaller housing with one input port, oneoutput port, and one enclosure for a single valve chip.

According to some embodiments of the present invention, air paths can beindependently controlled between each of the five chambers 143 a-e in avalve assembly configured for 5-way operations, so that the same valveassembly may function as an “All Cylinder Ports Exhausted” valve, as an“All Cylinder Ports Blocked” valve, or as an “All Cylinder PortsEnergized” valve. A valve assembly according to some embodiments of thepresent invention may thus replicate the functionality of anycommercially available valve type based on programming of theelectronics sub-assembly, selection of a program of the electronicssub-assembly, and/or insertion of packaged valve chip assemblies and/orsealing plugs into enclosures of the main housing.

Moreover, valve assemblies according to some embodiments of the presentinvention may provide independent control of airflow so that novel valvetypes may be implemented. With a back-up power source such as a battery,for example, a unique functionality may be provided when system power islost. More particularly, the valve and pneumatic actuator may retain alast position during a power failure (as opposed to assuming a defaultcondition).

In addition, circuits, such as custom integrated circuit devices (e.g.,application specific integrated circuit devices), for the electronicssub-assembly may provide different programs allowing the same physicalvalve assembly (including valve chips main housing, base, electronicssub-assembly, etc.) to provide functionality of any valve type. One of aplurality of programs of the electronics sub-assembly may be selected,for example, by pulling input pins to specific voltage levels, byprogramming a chip(s) of the electronic sub-assembly using an interface(such as a serial interface), selectively destroying fusible links,cutting and/or maintaining one or more jumpers, placing and/or omittinga shunt between two or more pins, selecting a position of a switch(es),etc.

Valve assemblies according to additional embodiments of the presentinvention may use pulse width modulation to control a flow of fluidthrough the electrostatically actuated valves. For example, pulse widthmodulation may be used to open and close electrostatically actuatedvalve flaps at a predetermined frequency with a duty-cycle being used todetermine a fluid flow through the valve. For example, a 100% duty cyclemay provide a full flow, a 50% duty cycle may provide half flow, and 0%duty cycle may provide no flow. By using pulse width modulation toactuate valve chips 131 a-d, for example, a speed at which the rod 167extends and retracts may be controlled. Moreover, an acceleration and/ordeceleration of the rod 167 may be controlled as the rod extends and/orretracts by varying the duty cycle as the rod extends or retracts. Forexample, respective valve chips may be actuated at a greater duty cycleat the beginning of extending and/or retracting to overcome inertia, andthe respective valve chips may be actuated at a reduced duty cycle asthe rod approaches the fully extended and/or retracted positions.

Moreover, one or more filters may be provided in valve assembliesaccording to some embodiments of the present invention. Filters may beprovided, for example, at high pressure supply port 144 c and/oractuator ports 146 a and 146 b. In addition or in an alternative,filters may be provided at exhaust ports 142 a and 142 b. Filters atsupply port 144 c and/or exhaust ports 142 a and 142 b may be providedon and/or in the base 601 of FIG. 18. Filters at actuator ports 146 aand 146 b may be provided inside or outside the main housing 401, insideor outside banjo fittings 415 a and 415 b, and/or at collets 419 a and419 b. The use of filters may protect the valve assemblies fromcontaminants such as dust, oil, and/or water that may degrade operationof the valve assemblies by plugging valve orifices and/or reducing aseal between valve flaps and respective orifices when a valve is closed.

Additional embodiments of a packaged valve chip (including a valve chip131 as discussed above with respect to FIG. 2) with a wedge shapedbaffle 741, a frame 711, and leads 717, are illustrated in FIGS. 24-26.Electrical leads 717 according to some embodiments of the presentinvention are illustrated in FIG. 27 separate from the frame 711.

As shown, for example, in FIGS. 24-26, a packaging frame 711 accordingto some embodiments of the present invention may include a body 713, agasket 715, and electrical leads 717. The frame 711 may have a windowtherein, a recessed ledge surrounding the window, and a trough maysurround the ledge as discussed above with regard to FIGS. 5-6 and/or7-8. A combined width of the ledge and trough may be in the range ofapproximately 0.025 inches to approximately 0.060 inches. Moreparticularly, a combined width of the ledge and trough may be in therange of approximately 0.050 inches to approximately 0.060 inches. Theelectrical leads 717 may be formed of stamped metal, and the electricalleads 717 may be plated with tin (approximately 150 micro inches) andthen plated with gold (approximately 40 micro-inches). The body 713 maybe formed of an injection molded insulating material (such as a plasticmaterial, an elastomeric material, a polymer, a co-polymer, and/orderivatives thereof), and the gasket 715 may be formed of an injectionmolded flexible sealing material such as rubber, viton, and/or silicone.The gasket 715 may provide a static fluid seal with respect to a mainhousing of a valve assembly.

More particularly, the body 713 may be formed by injection molding aninsulating material (such as a plastic material, an elastomericmaterial, a polymer, a co-polymer, and/or derivatives thereof) with theelectrical leads 717 being provided as inserts in the mold. Moreover,the gasket 715 may be formed together with the body 713 using a two-shotmolding process and/or an overmolding process. The ledge may be recessedrelative to a surrounding portion of the body 713 so that a valve chipcan be supported at edges thereof on one side by the ledge with top andbottom surfaces of the valve chip exposed for fluid communicationtherethrough. In addition, the ledge may be sufficiently recessed sothat a subsequently placed valve chip is also recessed within the body713. Moreover, portions of the electrical leads 717 are exposed adjacentthe window for electrical connection (such as by wire bonding, solderbumping, conductive epoxy, or other means known to those having skill inthe art) to a subsequently placed valve chip. In addition, notches 725in the body 713 may be provided adjacent portions of the ledge to allowroom for a tool to place a valve chip on the ledge with other portionsof the body 713 fitting more closely to the valve chip. Portions of thebody 713 surrounding the leads 717 may be angled (for example, atapproximately 30 degrees) to provide wire bonding tip clearance.

An adhesive can then be provided in the trough of the body 713, and avalve chip 131 can be placed on the ledge of the body 713 surroundingthe window, with the trough providing for placement, retention, and/orcontrol of spreading of the adhesive until it is fully cured. Moreparticularly, an adhesive bead having a width of approximately 0.015inches may be used. The valve chip may be placed on the ledge of thebody 713 with accuracy of approximately 0.005 inches using opticalsensor equipment. Accordingly, indication marks may be molded into thebody 713 of the packaging frame. More particularly, indication marks maybe molded to include perpendicular intersecting lines having anappearance similar to that of a “L”, “T”, “+”, or other similarcharacter. Moreover, the indication marks may have a depth ofapproximately 0.010 inches.

An adhesive used to secure the valve chip 131 on the ledge of the body713 may be cured at approximately 150 degrees C. (302 degrees F.) forapproximately 1 hour. In an alternative, the adhesive may be cured for alonger time at a lower temperature. Polycarbonate, for example, may beused for the body 713 and polycarbonate may have a melting temperaturein the range of approximately 430 degrees F. to approximately 480degrees F. To reduce deformation of the body 713, however, adhesive curetemperatures may be maintained in the range of approximately 125 degreesF. to approximately 200 degrees F. In an alternative, a W cured epoxymay be used as an adhesive.

Portions 729 of the body 713 may be deformed around the exposed edges ofthe valve chip 131 to provide the structure illustrated in FIG. 26. Theadhesive may provide a fluid seal between the valve chip 131 and thebody 713, and the deformed portions 729 may secure the valve chip withinthe body 713. More particularly, portions 729 of the body 713 may bedeformed using a heated tool (such as a heat stake) to retain the valvechip 131 within the body 713. Accordingly, edges of the valve chip 131may be supported on one side by the ledge of the body 713 and on theother side by the deformed portions 729 of the body 713. Moreover, asurface of the valve chip 131 adjacent the leads 717 may be recessedapproximately 0.010 inches relative to the leads 717 and approximately0.030 inches relative to a surface of the body 713 surrounding thenotches 725, ledge, and trough.

On the valve chip 131, all fixed electrodes may be electricallyconnected to a first input pad (such as a first gold bond pad), and allflexible electrodes may be electrically connected to a second input pad(such as a second gold bond pad), and the input pads may be electricallyconnected (e.g., via wire bonding such as gold wire bonding, solderbumping, conductive epoxy, or other means known to those having skill inthe art) to exposed portions of respective electrical leads 717 adjacentthe window through the body 713. A glob-top potting 731 can be used toprotect the electrical connection between the input pads of the valvechip 131 and the electrical leads 717. Portions of the electrical leads717 are exposed on an edge of the body 713 for electrical coupling to amain housing of a valve assembly.

According to alternate embodiments, the packaging frame 711 may use achip gasket similar to that discussed above with regard to FIGS. 7 and 8to provide a fluid seal between the valve chip 131 and the body of thepackaging frame. As before, the body 713 may be formed of injectionmolded insulating material (such as a plastic material, an elastomericmaterial, a polymer, a co-polymer, and/or derivatives thereof), and thegasket 715 discussed above and the additional chip gasket may be formedof an injection molded flexible sealing material such as rubber, viton,and/or silicone. The gasket 715 may provide a static fluid seal withrespect to a main housing, and the chip gasket may provide a staticfluid seal with respect to a valve chip placed thereon. Moreover, thegasket 715 and the chip gasket may be formed together with the body 713using a two-shot molding process and/or an overmolding process. In analternative to a chip gasket or in addition, a stamped adhesive tape maybe used to secure the valve chip to the ledge.

Moreover, the valve chip 131 may be packaged before releasing the valveflaps 117. More particularly, the valve flaps 117 may be formed on asacrificial oxide, and the sacrificial oxide may be maintained while thevalve chip 131 is being assembled in the packaging frame. Thesacrificial oxide may then be removed using a dry (vapor) HF releasewithout significantly damaging the packaging frame. More particularly,the packaging frame may be formed of viton and/or other materials whichmay be resistant to damage from a dry (vapor) HF release.

In an alternative, valve flaps of a valve chip may be released byremoving sacrificial oxide using a wet HF acid etch either before dicingfrom a wafer including a plurality of valve chips, after dicing butbefore packaging, or after packaging. More particularly, the sacrificialoxide layer may be removed from the valve chip using a 49% HF solutionfor approximately 10 minutes, and the wet etch may be followed by ade-ionized (DI) water rinse, an isopropyl alcohol rinse, and first andsecond methanol rinses for 20 minutes each to remove any residual HFand/or water. After the wet processing, the valve chip with the releasedvalve flaps may be primed with methanol for a supercritical dry cycle toreduce any surface tension that may otherwise result in stiction betweenvalve flaps and the substrate.

More particularly, the valve chip may be loaded into a dryer chamber andcovered with methanol, and liquid CO₂ may then be used to displace themethanol from the chamber at a pressure of approximately 1200 psig. Onceall of the methanol is displaced, the chamber is heated past thesupercritical point (approximately 31 degrees C.) to transition the CO₂from the liquid to gas phase, and the pressure is released to vent thesystem of CO₂ vapor. Because supercritical CO₂ has extremely low surfacetension, CO₂ is less likely to pull the valve flaps down as ittransitions from liquid to gas. Commercially available and/or customsupercritical dryers may be used.

Visual inspection can be used to determine that an acceptable number ofthe valve flaps on a valve chip are successfully released. Inparticular, a surface of the valve chip has a different color thanexposed silicon under the flappers which is visible when the valve flapsare released and the valve chip is unpowered, and the color variationscould be inspected. In an alternative, light can be projected throughthe wafer after release, and an optical detector could detect lightdifferences between the unreleased (closed) and released (open) valvechip. In either example, machine vision systems could be used to performthe inspections.

Moreover, tooling used to mold packaging frames according to someembodiments of the present invention illustrated in FIGS. 24-26 may beadaptable so that packaging frames with the same outer dimensions aremolded with different window dimensions using substantially the samemold tooling. For example, a same mold base could be used to formdifferent packaging frames with different mold lids being used toprovide different window sizes, shapes, and/or locations. Accordingly,packaging frames may be efficiently fabricated for valve chips ofdifferent sizes. More particularly, a smaller window may be provided fora smaller valve chip for an application requiring a lower fluid flowcapacity, and the smaller window may be provided adjacent the electricalleads (instead of being centered) to provide proximity for wire bonding.By providing the packaging frames with the same outer dimensions fordifferent valve chip sizes, a same main housing may receive packagedvalve chips of different capacities/sizes to provide different operatingcharacteristics.

As further shown in FIGS. 24-26, a wedge shaped baffle 741 may beprovided on the body 713 of the frame 711 to deflect pressure spikesand/or reduce stress on the electrostatic valve flaps of the valve chip131. More particularly, the baffle 741 may be provided on the body 713adjacent the side of the valve chip 131 including the flexible valveflaps and input pads. By including the baffle 741, valve flaps 117 ofthe valve chip 131 may be protected during handling and subsequentassembly. In addition, the baffle 741 may provide a more laminar flowthough the valve chip 131, increase a speed of sequencing a valveassembly including packaged valve chips with the baffle, and/oreliminate a need for sequencing. While the baffle 741 is illustratedwith four generally circular orifices 743, different shapes,configurations, and/or orientations may be provided, and/or lessernumbers of orifices such as a single orifice may be provided.

The baffle 741 may attach to the body 713 of the frame 711 using fourpins 745 a-b and 747 a-b and a heat stake operation. More particularly,the pins 745 a-b may be molded onto the body 713 of the frame 711 andconfigured to mate with through holes 749 a-b molded into the baffle741. The pins 747 a-b may be molded onto the baffle 741 and configuredto mate with through holes 751 a-b molded into the body 713 of the frame711. By arranging the pins 745 a-b and 747 a-b and through holes 749 a-band 751 a-b as illustrated in FIGS. 24-26, a desired orientation of thebaffle 741 relative to the body 713 can be provided thereby reducingassembly errors. In other words, the placement of pins and holesillustrated in FIGS. 24-26 can facilitate that a relatively thin portionof the wedge shaped baffle 741 is arranged adjacent the electrical leads717, and a relatively wide portion of the wedge shaped baffle 741 isarranged distant from the electrical leads 717. The baffle 741 may bemolded from a same material used for the body 713, or a differentmaterial may be used.

The through holes 749 a-b in the baffle 741 may be provided withcounter-bores (i.e., wider portions) opposite the body 713, and thethrough holes 751 a-b in the body 713 may be provided with counter-boresopposite the baffle 741. Accordingly, the pins 745 a-b and 747 a-b maybe mated with respective through holes 749 a-b and 751 a-b, and a heatstake operation on the pins may be used to secure the baffle 741 to thebody 713. By providing counter-bores for the through holes, room formovement of heat staked material from the pins may be provided so thatoutside faces of the baffle 741 and/or the body 713 are notsignificantly deformed as a result of the heat stake operation.

As further shown in FIGS. 24-26, the baffle 741 may include a pluralityof orifices 743 therethrough. Moreover, the baffle 741 may be providedadjacent a flapper side of the valve chip 131, and the gasket 715 may beprovided adjacent a backside of the valve chip 131. A backside of thevalve chip 131 may thus communicate with a high pressure environment(such as a chamber), the orifices 743 of the baffle 741 may communicatewith a relatively low pressure environment (such as a chamber), and thevalve chip 131 may allow or block flow from the high pressureenvironment through the valve chip and through the orifices 743 in thebaffle 741 to the low pressure environment. Accordingly, the baffle 741may protect the flapper side of the valve chip 131 during handlingand/or subsequent assembly.

In addition, the baffle 741 may control a pressure differential acrossthe valve chip 131, so that the flappers of the valve chip 131 are notrequired to open and/or close against sonic air flow and/or against fullinput pressure. By providing the baffle 741, a reservoir is providedbetween the baffle 741 and the valve chip 131 so that a flow may berestricted and/or so that a pressure against which the valves must closemay be reduced. Stated in other words, a total pressure drop across thepackaged valve chip may be split between a first pressure drop acrossthe valve chip 131 and a second pressure drop across the baffle 741 sothat the total pressure drop is not felt across the valve chip 131.Because the baffle 741 may allow valve flaps of the valve chip 131 usedin a valve assembly to open and/or close in relative short periods oftime (e.g., in less than 100 microseconds) against a reduced pressure,fluid flow through the valve chip 131 may be directed “at will” withoutrequiring particular sequencing steps as discussed above, for example,with regard to FIGS. 4A-F. In other embodiments, sequencing operationsof FIGS. 4A-F may be used together with valve chips 131 packaged withbaffles 741 to provide operation at even higher pressures.

Sizes, locations, and numbers of the orifices 743 may be used to controlback pressures and fluid flows thorough the valve chip 131 and assembly.As shown in FIGS. 24-26, the orifices 743 may be provided adjacentoutside corners of the valve chip 131, but other orientations,positions, shapes, etc. of orifices 743 may be provided. With the baffle741, valve flappers of the valve chip 131 may open and/or close againstonly a fraction of a total pressure across the assembly including thebaffle 741 and the valve chip 131, and periods of turbulent flow may bereduced. Accordingly, response times to open and/or close the valveflaps may be reduced, improved functionality may be provided, and/orreliability may be improved. Moreover, a need for sequencing may beeliminated.

The wedge shape of the baffle 743 may also facilitate assembly of thepackaged valve chip into a main housing. More particularly, the wedgeshape may allow the packaged valve chip to be inserted approximately ¾(i.e., 75%) of the way into a corresponding wedge shaped enclosure of avalve housing before the gasket 715 begins to compress. Accordingly,damage to the gasket 715 during subsequent assembly may be reduced.

As shown in FIGS. 24-26, the gasket 715 may be provided on a side of thebody 713 adjacent the backside of the valve chip 131 and opposite thebaffle 741. The gasket 715 may thus be protected from adhesives, heatstake operations, etc. used to secure the valve chip 131 in the body 713during assembly. By placing the gasket 715 as shown in FIGS. 24-26,interference between the gasket 715 and the baffle 741 may be reduced.

Moreover, the electrical leads 717 may be formed as shown in FIG. 27 sothat wire bond portions 717 a of the leads are substantially parallel tothe valve chip 131 and so that external portions 717 b of the leads aresubstantially perpendicular with respect to the valve chip 131.Moreover, dimples 717 c may be provided on the external portions 717 bof the leads to improve interconnection with leads of a main housing.

The packaged valve chips of FIGS. 24-26 can be plugged in and out of amain housing as discussed in greater detail with respect to FIGS. 28-34.Accordingly, a valve assembly including one or more packaged valve chipsmay be repairable and/or adaptable. A valve assembly with amalfunctioning valve chip may thus be repaired by removing the packagedvalve chip that is not working and inserting a new packaged valve chip.In addition, functionality of a valve assembly may be changed byreplacing original packaged valve chips with new packaged valve chipshaving a different characteristic (such as different flow capacityand/or size of valve chip).

A main housing 801 according to some embodiments of the presentinvention is illustrated in FIGS. 28-31. More particularly, an explodedview of a main housing 801 and associated components is illustrated inFIG. 28, and a bottom perspective view of the main housing isillustrated in FIG. 31. As shown in the bottom view of FIG. 31, the mainhousing 801 defines valve assembly chambers 143 a-e discussed above withrespect to FIGS. 3 and 4A-F. The main housing 801 also includesenclosures 803 a-d configured to receive packaged valve chips (such asdiscussed above with respect to FIGS. 24-27) perpendicular to a lengthof the main housing. In addition, main housing 801 includes conductiveleads 805 therein used to transmit signals to metal leads 717 of thepackaged valve chips in enclosures 803 a-d. A perimeter base gasket 807may be included to provide a fluid seal with respect to a base of theassembly (illustrated, for example in FIGS. 37 and 38), and a PCB gasket809 may be included to provide a seal for an external connection to theleads 805 of the main housing.

The main housing 801 may be formed by injection molding an insulatingmaterial (such as a plastic material, an elastomeric material, apolymer, a co-polymer, and/or derivatives thereof) with conductive leads805 insert molded therein, and the gaskets 807 and/or 809 may be formedof a flexible sealing material using a two-shot molding process and/oran overmolding process. More particularly, the molding tool creates thefive separate chambers 143 a-e for high pressure air supply and lowpressure exhaust as discussed above with respect to FIGS. 3 and 4A-F.When injection molding the main housing, a hole may be included in theoutside of the housing to accommodate formation of interior holesbetween chambers 143 a-e, and the hole in the outside of the housing maybe sealed with a plug that may be glued, welded or otherwise affixed toseal the hole.

As shown in FIGS. 28-30, the main housing 801 may also have banjofittings 815 a-b, O-rings 817 a-b, and collets 819 a-b (also referred toas quick connect fittings and/or cartridges) affixed thereto. Moreparticularly, the collets 819 a-b may be push-in style cartridges. Moreparticularly, the banjo fittings 815 a-b may be affixed to the mainhousing 801, for example, using ultrasonic welding and/or an adhesive,and the banjo fittings 815 a-b are in fluid communication with thechambers 143 b and 143 d of the valve assembly. The O-rings 817 a-b andthe collets 819 a-b may then be inserted in the banjo fittings 815 a-bfor retention of air-tubes providing fluid communication with thepneumatic actuator chambers 163 a-b (shown in FIG. 3). The main housing801 can be used to provide either a three-way valve or a five-way valvedepending on the number of packaged devices used and locations thereofto control fluid flow.

As discussed above, a microelectromechanical systems (MEMS) valve chip131 may be packaged in a frame to provide a packaged valve chip asillustrated, for example, in FIGS. 24-26. Packaged valve chips may beselectively plugged in and out of respective enclosures 803 a-d of themain housing 801 so that the valve assembly is adaptable and/orrepairable. The gasket 715 of the packaged valve chip provides a fluidseal with the respective enclosure 803 a-d so that fluid communicationbetween enclosures is only provided through openings in respective valvechips. Moreover, the valve chip 131 in a packaged valve chip isdirectional and the gasket 715 should mate with a predetermined side ofthe particular enclosure so that the packaged valve chip is oriented inthe main housing 801 to provide the fluid flows between chambers 143 a-ediscussed above with respect to FIGS. 4A-F.

As shown in FIG. 32, each of the enclosures 803 a-d (shown in FIG. 31)may have a wedge shaped profile to accept a respective packaged valvechip including a wedge shaped baffle 741 as discussed above with regardto FIGS. 24-27. More particularly, each of the enclosures 803 a-d mayhave a profile that is relatively wide adjacent a base 851 for thehousing 801 and that becomes more narrow as the enclosure extends awayfrom the base 851. Accordingly, each of the enclosures 803 a-d may beconfigured to receive a respective packaged valve chip (including awedge shaped baffle 741) with a narrow portion of the packaged valvechip and leads 717 extending into the housing and with a wide portion ofthe packaged valve chip adjacent the base 851 for the housing 801.

The possibility that a packaged valve chip is incorrectly inserted intothe housing can be reduced because a wide portion of the wedge shapedpackage cannot be inserted into the housing first. For example, thewedge shape of the enclosure may reduce the possibility that the wedgeshaped chip assembly can be inserted upside down or sideways. Moreover,complete insertion may not be possible if the wedge shaped chip assemblyis inserted into the enclosure backwards so that the base 851 may notproperly mate and/or form a seal with the housing 801.

In addition, the wedge shaped package may be inserted a significantportion (e.g., greater than 50%, and frequently as much as 75%) of theway into the respective wedge shaped enclosure before the gasket 715 ofthe package begins to compress. Accordingly, damage to the gasket 715can be reduced, and/or an improved fluid seal may be provided betweenthe wedge shaped package and the wedge shaped enclosure.

As discussed above, an interior dimension of a window of a frame used topackage a valve chip can be varied to accommodate valve chips ofdifferent sizes without varying outer dimensions of the packaged valvechip assembly. A same main housing 801 may thus receive packaged valvechip assemblies in enclosures 803 a-d having different flow capacitycharacteristics. Stated in other words, the size of a MEMS valve chipmay be varied to provide different flow characteristics (for example, inthe range of approximately 0.001 Cv to approximately 10 Cv) whilemaintaining a same envelope geometry of the packaged valve chip.

In addition, exposed portions of the metal leads 717 on an edge of thepackaged valve chip may mate with corresponding leads 805 of the mainhousing 801 to provide communication of electrical signals from outsidethe main housing with fixed and flexible electrodes of the valve chipsplugged into enclosures 803 a-d of the main housing 801.

FIG. 33 illustrates a valve assembly including four packaged valvechips, an electronics sub-assembly 1001, and a base 851 withnon-metallic portions of the main housing 801 omitted. Accordingly, theelectrical leads 805 of the main housing 801 are visible, and a couplingof the electrical leads 805 of the main housing and the electrical leads717 of the packaged valve assemblies is also visible.

As shown in FIG. 33, a bend may be provided in each of the electricalleads 805 so that portions (or tabs) of the electrical leads 805 makingcontact with the leads 717 of the packaged chip assembly may be providedparallel with respect to a length of the leads 805 (and parallel withrespect to a length of the main housing 801). Accordingly, the portionsof the electrical leads 805 making contact with the leads 717 may besupported on both ends thereof for added strength. Moreover, as thepackaged chip assembly is inserted into the enclosure of the mainhousing, the leads 717 of the packaged chip assembly may slide backand/or forth along the tabs of the leads 805 as the gasket 715 iscompressed during insertion. A reliability of electrical couplingbetween the leads 717 and 805 can thus be improved.

In addition, filters may be provided in one or more of the chambers 143a-e to protect the microvalves. For example, exhaust filters 1041 may beprovided in chambers 143 b and 143 c, and input filter 1043 may beprovided in chamber 143 c, as shown in FIG. 34. A filter in chamber 143c may protect microvalves from particles and/or other debris from a highpressure supply, and filters in chambers 143 b and 143 d may protectmicrovalves from particles and/or other debris introduced from ports tothe actuator. The filters 1041 and/or 1043 may be manufacturedintegrally with the housing 801, and/or the filters 1041 and/or 1043 maybe manufactured separately from the housing 801. One or more of thefilters, for example, may be porous plastic filters, porous metalfilters, paper filters, desiccant filters, coalescing filters, fiberfilters, membrane filters, mesh filters/separators, mist separators,vane separators, cyclonic separators, down flow separators, rain outseparators, vertical flow separators, and/or horizontal separators.

The input filter 1043 may be used to filter a high pressure supplyprovided by the customer. While the high pressure supply may be filteredoutside the housing 801, damaging particles may be introduced into thehigh pressure supply during valve installation, and/or particles mayotherwise be introduced downstream from any external filtering. By wayof example, the input filter 1043 may be configured to catch materialssuch as particles of Teflon® tape, pipe sealant, and/or other particlesthat may be in a high pressure supply pipe downstream from thecustomer's high pressure supply filter/regulator. Accordingly, damage tovalve chips in supply paths may be reduced. Moreover, the input filter1043 may be configured to allow air flow in all directions. Accordingly,if one area of a filter becomes clogged with contaminants, air can flowthrough adjacent areas of the filter without significantly limiting,flow. While the supply filter 1043 is shown in the housing 801, otherfilters may be provided in place of and/or in addition to the supplyfilter 1043. For example, a supply filter may be provided in the base851, and/or in a supply line coupled to the base.

The exhaust filters 1041 may be used to filter actuator exhaust that mayinclude particles generated as a result of actuation. Actuator exhaust,for example, may include minute particles of dried lubricant, seal, rodbearing, and/or actuator body material. By filtering any such particlesfrom the actuator, damage to the valve chips in exhaust paths can bereduced. Moreover, the exhaust filters 1041 may be configured to allowair flow in all directions. Accordingly, if one area of a filter becomesclogged with contaminants, air can flow through adjacent areas of thefilter without significantly limiting flow. While the exhaust filters1041 are shown in the housing 801, other filters may be provided inplace of and/or in addition to the exhaust filters 1041. For example,exhaust filters may be provided in banjo fittings 815 a-b, in collets819 a-b, and/or in the pneumatic actuator.

The use of a baffle 741 may provide a baffle chamber between the baffleand the associated valve chip with the valve flaps of the valve chipphysically protected in the baffle chamber during handling and/orassembly. Moreover, an orifice(s) in the baffle may sufficientlyrestrict fluid flow so that a maximum force applied to the valve flapsof the valve chip may be reduced. In addition, a volume of the bafflechamber may be sufficiently small relative to the associated chamber ofthe valve housing so that a laminar fluid flow through the valve chipcan be attained more quickly and so that fatigue of the valve flaps canbe reduced. Baffles and sequencing operations (as discussed with respectto FIGS. 4A-F) can thus be used separately or in combination to increasepressures against which the valve chips can operate, to reduce fatigue,to improve flows, etc.

Moreover, baffles with orifices of different sizes may be provided fordifferent valve chips in a same valve assembly. The 5-way valve of FIG.34, for example, may be provided with baffles 741 b-c providing greaterflows into actuator ports and with baffles 741 a and 741 d providingmore restricted flows out of actuator ports. Relatively smooth pistonmotion may be provided, and/or maximum piston velocities may be reduced.

An electronics sub-assembly 1001 for valve assemblies according to someembodiments of the present invention is illustrated in FIGS. 35-36. Moreparticularly, a printed circuit board within the electronicssub-assembly 1001 may include electronic circuitry and/or softwareand/or firmware used to control operations of the valve chips 131included in the main housing 801. For example, the printed circuit boardmay include electronic circuitry and/or software to control and/or drivethe valve chips 131 in accordance with operations discussed above withrespect to FIGS. 4A-F as instructed by a remote device such as aprogrammable logic controller (PLC).

The printed circuit board may include integrated circuit chips,resistors, capacitors, and/or inductors thereon. In addition, leads onthe printed circuit board may provide electrical coupling with leads 805of the main housing 801, and a connector 1005 (such as a 5-pin Molexconnector) may provide electrical connection to a remote controller suchas a PLC. The electronics sub-assembly may be configured to provide aplurality of different operating characteristics defined in memory (suchas ROM, PROM, EPROM, EEPROM, etc.) with one particular programmingcharacteristic being selected using means such as a jumper(s), a dipswitch(es), shunt(s), etc. More particularly, the printed circuit boardmay include one or more custom circuits (for example, including one ormore application specific integrated circuit ASIC devices) as discussedbelow with respect to FIGS. 41-44, 45A-B, and 46A-B. Additionaloperations of valve assemblies and/or electronic sub-assemblies thereofare discussed in the U.S. Provisional Application No. 60/590,699 toKevin Douglas et al., entitled “Methods Of Operating ElectrostaticallyActuated Microvalve Assemblies And Related Structures” and filed Jul.23, 2004 (hereinafter “Douglas et al.”). The disclosure of thisprovisional application is hereby incorporated herein in its entirety byreference.

During normal operation, the electronics sub-assembly 1001 may receiveoperating power along with control signals through connector 1005. Analternate power source such as a battery 1013 may also be provided sothat the electronics sub-assembly can sequence the valve chips 131 to apredetermined default condition in the event of a power outage. While abattery is shown in FIGS. 35 and 36, other alternate power sources (suchas a capacitive storage device and/or a fuel cell) could be used. Asshown in FIGS. 35 and 36, the battery 1013 may be provided in a hingedcompartment cover 1015 so that the battery may be replaced. Hinges 1017may provide that the compartment cover opens and closes, and gasket 1019may protect the battery 1013 from contamination and/or moisture outsidethe battery compartment. The battery compartment may be formed using atwo-shot process to provide an integral cover 1015 and gasket 1019. Witha disk type battery, terminals 1021 may provide electrical couplingbetween electronics of the sub-assembly and the battery 1013. Moreover,the electronics sub-assembly may include circuitry configured to chargethe battery during normal operations using externally provided power.Accordingly, a life of a battery may be extended.

Moreover, indicator lights 1023 (such as light emitting diodes) mayprovide indication of a current mode of operation, an external powersupply status, a battery status, etc. In addition, pairs of manualoverride contacts 1025 may be used to manually drive an associatedactuator to either the extended or retracted position. For example, afirst pair of manual override contacts may be electrically shorted withthe tip of a screwdriver or other tool to manually drive the associatedactuator to a retracted position, and a second pair of manual overridecontacts may be electrically shorted with the tip of a screwdriver (orother tool) to manually drive the associated actuator to an extendedposition.

The electronics sub-assembly 1001 may also include a high voltage drivecircuit (such as a multiple stage charge pump) used to drive the valvechip electrodes. For example, a 24V external power supply may beprovided through the connector 1005, and a high voltage drive circuitmay generate a 150V output used to drive the valve chip electrodesthrough leads 805 of the housing 801 and leads 717 of the valve chips.The printed circuit board may also include a transient voltagesuppressor (TVS) such as a pair of serially connected and opposing zenerdiodes.

A controller of the electronics sub-assembly may be configured tomonitor the external power supply, and upon detecting interruption ofthe external power supply, to advance the valve chips 131 a-d to apredetermined default condition and to hold that default condition usingenergy provided from the alternate power source. Upon detectinginterruption of the external power supply, for example, the currentcondition of the valve chips 131 a-d may be maintained. In analternative, upon detecting interruption of the external power supply,the controller may close the valve chips 131 a-d so that fluidcommunication is blocked between each of the chambers 143 a-e. Inanother alternative, upon detecting interruption of the external powersupply, the controller may close valve chips 131 b-c and open valvechips 131 a and 131 d. In still another alternative, upon detectinginterruption of the external power supply, the controller may closevalve chips 131 a and 131 d and open valve chips 131 b-c.

The electronics sub-assembly 1001 including a printed circuit board maybe encapsulated in an insulating material (such as a plastic material,an elastomeric material, a polymer, a co-polymer, and/or derivativesthereof) as illustrated in FIGS. 35 and 36, for example, using anover-molding process. More particularly, an epoxy may be used that canbe cured at a relatively low temperature and pressure to protect theelectronics therein. An external geometry of the encapsulatedelectronics sub-assembly may be provided that fits on the main housing801 so that the leads of the electronics sub-assembly mate with theleads 805 of the main housing 801.

The five pin connector 1005, for example, may provide an electricalpower (Vcc) input connection, a ground (GND) input connection, A and Binput control connections, and a power status output connection.Moreover, each pair of manual override contacts 1025 may be recessed inthe over-molded housing to reduce the possibility of accidental contacttherewith. In addition, the pairs of manual override contacts may berespectively labeled “2” and “4” on adjacent portions of the batterycover to correspond with actuator port numbers of the housing.

In addition, an extension 888 of the over-mold may be configured toguide placement of the electronics sub-assembly 1001 with respect to abase and a housing during subsequent assembly. More particularly, theextension 888 may mate with a corresponding slot of a base discussedbelow with respect to FIGS. 37-38. Moreover, the grooves 885 of theelectronics sub-assembly 1001 may be configured to mate with a retainingclip as discussed with respect to FIGS. 39 and 40.

A base 851 for valve assemblies according to some embodiments of thepresent invention is illustrated in FIGS. 37 and 38. The base 851 may beformed using a metal casting process. More particularly, the base 851may be formed of a metal such as aluminum or stainless steel, and theexhaust ports 142 a-b and the supply port 144 c may be threaded tappedholes. Additional screw tapped holes 853 a-b may be used to secure themain housing 801 onto the base 851. In addition, clearance and/ormounting holes 855 (perpendicular to and/or parallel with the ports) maybe provided in the base for mounting the valve assembly. Moreover,communication slots 857 provide relatively narrow openings between thescrew tapped holes and the respective chambers in the main housing 801.

By using a cast metal as the base, an integrity of the threads in theholes may be more easily maintained. Moreover, an epoxy finish may beprovided on a cast aluminum base for protection and/or aestheticpurposes. In an alternative, the base 851 may be formed from injectionmolded material (such as a plastic material, an elastomeric material, apolymer, a co-polymer, and/or derivatives thereof) using metallicinserts at threaded locations. As shown in FIG. 37, a groove 889 may beformed in a tang of the base 851, and the groove 889 may be configuredto receive the extension 888 of the electronics sub-assembly 1001.Grooves 887 may also be formed in the base 851 to couple with aretaining clip as discussed below with respect to FIGS. 39 and 40.

Moreover, the exhaust ports 142 a-b and the supply port 144 c may beflat bottom tap drilled and then tapped. In addition, the communicationslots 857 for the exhaust ports 142 a-b may be formed off-center.Accordingly, a length of the valve assembly may be reduced because theexhaust ports do not need to be centered relative to the respectivevalve chambers.

The valve assembly may be completed by plugging packaged valve chips(such as illustrated in FIGS. 24-26) into enclosures in the bottom ofthe main housing 801 (as shown in FIGS. 31 and 32); securing the mainhousing (including the packaged valve chips therein) to the base 851using screws 861; and attaching the electronics sub-assembly 1001 ontothe main housing 801 and base 851 using a U-shaped retaining clip 881 asshown in FIGS. 39 and 40. More particularly, the U-shaped retaining clip881 may be configured to couple with grooves 883 of the main housing801, with grooves 885 of the electronics sub-assembly 1001, and withgrooves 887 of the base 851 to fasten the components together. Moreover,the extension 888 of the electronics sub-assembly 1001 may be configuredto mate with the slot 889 of the base 851 to provide alignmenttherebetween.

The same main housing, base, and electronics sub-assembly can beconfigured for 5-way, 4-way, 3-way, or 2-way valve operations. For 5-wayoperations, as discussed above with respect to FIGS. 4A-F, four packagedvalve chips may be plugged into respective enclosures in the bottom ofthe main housing as shown, for example, in FIG. 34. For 3-way valveoperations, a packaged valve chip may be plugged into each of the twoenclosures most distant from the electronics sub-assembly, and a sealingplug may be plugged into the two enclosures closest to the electronicssub-assembly so that chambers 143 d-e are permanently sealed. Asdiscussed above, a same electronics sub-assembly may be configured toprovide one of a plurality of modes of operation defined in memory (suchas ROM, PROM, EPROM, EEPROM, etc.) depending on a selection made using ajumper(s), a switch(es), a shunt(s), a fuse(s), or other selectiondevice that can be set during and/or after manufacture. For example, asame electronics sub-assembly can be used to control either 5-way,4-way, 3-way, or 2-way operations depending on a switch, shunt, fuse,and/or jumper setting. For example, 3-way and 5-way valve operations arediscussed in Douglas et al.

In further alternatives, a main housing, base, and electronicssub-assembly can be configured for 4-way and/or 2-way valve operations.For 4-way operations, the base may be modified so that fluid coupling isprovided between exhaust chambers 143 a and 143 e and a same exhaustport. Otherwise, 4-way operations may be provided with four valve chipsas discussed above with respect to FIGS. 4A-F. In an alternative, 2-wayoperations may be provided using a single valve chip to provide aunidirectional on/off flow device. A 2-way device could be providedusing the components of FIGS. 28-31 with one valve chip and plugssubstituted for other valve chips. In an alternative, a 2-way devicecould be provided using a smaller housing with one input port, oneoutput port, and one enclosure for a single valve chip.

According to some embodiments of the present invention, electricalfunctionalities of the electronics sub-assemblies discussed above withregard to FIGS. 14-17 and/or 35-36 may be provided using a customcircuit (for example, including one or more Application SpecificIntegrated Circuits also referred to as ASICs). FIG. 41 is a blockdiagram illustrating functional blocks of a circuit 2001 according tosome embodiments of the present invention, and FIG. 42 is a schematicdiagram illustrating elements of a printed circuit board including thecircuit 2001 of FIG. 41.

As shown in FIG. 41, the circuit 2001 may include a powerregulation/control circuit 2011, a high voltage generation circuit 2013,a battery detect/control circuit 2015, a deglitch/debounce logic circuit2017, a sequence controller (state machine) circuit 2019, a high voltage(HV) output level shifter circuit 2021, a configuration circuit 2023, areversal timing/control circuit 2025, and a light emitting diode (LED)driver circuit 2027. As shown, the power regulation/control circuit 2011may receive external power supply VDD and ground GND signals throughrespective ones of the connectors 509 of FIGS. 14-17, or throughrespective ones of the connectors 1005 of FIGS. 35-36. Similarly, thedeglitch/debounce logic circuit 2017 may receive input controls signalsA and B through respective ones of the connectors 509 of FIGS. 14-17, orthrough respective ones of the connectors 1005 of FIGS. 35-36. Thebattery detect/control circuit 2015 may receive the battery power supplyVBat and ground GBat signals from a battery (such as battery 513 ofFIGS. 14-17 or battery 1013 of FIGS. 35 and 36).

The outputs F1-F4 and HComO and BComE of the HV output level shiftercircuit 2021 are used to drive the valve chips of the valve assemblywith the outputs F1-F4 and HComO and HComE being coupled to respectivevalve chips through leads of the main housing (such as through leads 405of FIGS. 13 and 20 or through leads 805 of FIGS. 31 and 33). Moreparticularly, the valve chips of the valve assemblies may be identifiedas first (most distant from the electronics sub-assembly) through fourth(closest to the electronics sub-assembly) with the high voltage outputsF1 to F4 being respectively applied to the first through fourth valvechips, with the High Voltage Common Odd HComO signal being applied tothe first and third valve chips, and with the High Voltage Common EvenHComE signal being applied to the second and fourth valve chips.

The configuration logic circuit 2023 may receive configuration selectsignals C1-C3 which may be either grounded or floating. As shown in FIG.42, the circuit 2001 may be provided on a printed circuit board witheach of the configuration select signals/pins C1-C3 either coupled toground through a respective jumper J1-J3 or floating (by removing therespective jumper). In an alternative, traces to ground for respectiveconfiguration select signals/pins C1-C3 may be either maintained or cutbefore packaging to provide that respective configuration selectsignals/pins are either grounded or floating. Moreover, the LED drivercircuit 2027 outputs LED-A and LED-B may drive respective LEDs 1023.

The custom circuit of FIGS. 41 and 42 may be configured so that theresulting valve assembly can be used as a drop-in replacement for aconventional solenoid driven valve. Accordingly, the physical andelectrical interfaces for the electronics sub-assembly may conform tophysical and electrical interfaces used for conventional solenoid drivenvalves. For example, the deglitch/debounce logic circuit 2017 may beconfigured to receive input controls signals A and B used for solenoiddriven valves. As shown in FIGS. 41 and 42, four separate high voltageoutput signals F1-F4 may be provided, and each valve chip load caneffectively be modeled as a capacitor VC1-VC4 with hysteresis. Thecapacitors VC1-VC4 thus represent valve chips provided in a main valvehousing as opposed to elements provided on a printed circuit board in anelectronics sub-assembly. Moreover, the high actuation voltages may begenerated using charge pumps, inductor circuits, and/or combinationsthereof, and/or other circuits known to those having skill in the art.

The high voltage generation circuit 2013 may be configured to convert alow voltage source (such as a 24 Volt external power supply signal VDDand/or a 3 Volt battery power supply signal VBat) to a high voltagesignal, such as a 200 Volt DC signal. The HV generation circuit 2013,for example, may include a series of charge pumps provided on thecircuit 2001. In addition or in an alternative as illustrated in FIGS.41 and 42, external inductor coils LL and LH may be provided in parallelwith external resistors RL and RH to provide one or more boostconverters used to generate high voltage signals while reducing a sizeand/or cost of the circuit 2001. Moreover, an absolute value of the highvoltage(s) thus generated may be adjusted to accommodate differentactuation voltages used for different applications and/or to accommodatevariations in characteristics of different circuits (such as ASICs)resulting from manufacturing variations. The resulting high voltages maybe adjusted using a resistor HVAR as part of a divider used with acomparator of the HV generation circuit 2013 to control when the highvoltage generation circuit 2013 is active.

Upon loss of the primary power source (e.g., upon loss of the externalpower supply signal VDD), an electronic sub-assembly including thecircuit 2001 may be configured to provide that the valve assembly canmaintain a state or transition to a desired state. Accordingly, theelectronic sub-assembly including the circuit may be configured toprovide sufficient energy from a battery (such as battery 513 of FIGS.15-17, battery 1013 of FIG. 36, and/or battery 3013 of FIG. 42) toovercome leakage through the electrostatically actuated valve chipswhile maintaining the valve chips in a desired state for an indefiniteperiod during loss of the external power supply signal VDD (which may bea 24 Volt supply).

Upon detection of a power loss, energy may also be needed to switch thehigh voltage output signals F1-F4 to a predefined condition, dependingupon a particular application and state of the inputs at the time of thepower loss. A relatively low-cost 3 Volt lithium primary battery may beused to provide energy to maintain high voltage output signals F1, F2,F3, and/or F4 when the DC external power supply signal VDD is lostand/or interrupted. In an alternative, a rechargeable lithium ionbattery having a voltage output in the range of 3.0 to 4.2 Volts may beused, with the circuit 2001 being configured to recharge the batterywhen the external power supply signal VDD is present.

During normal operation with the external power supply signal VDDavailable, the deglitch/debounce logic circuit 2017 may receive and/orfilter the input control signals A and B, and the deglitch/debouncecircuit 2017 may provide the input control signals A and B to thesequence controller 2019. With the external power supply signal VDDavailable, the sequence controller circuit 2019 directs operation of theHV output level shifter circuit 2021 in accordance with the inputcontrol signals A and B and in accordance with a circuit configurationdefined by the configuration signals C1-C3. During loss of the externalpower supply signal VDD, the battery detect/control circuit 2015 maydetect the power loss, and a power loss signal may be generated by thedetect/control circuit 2015 and provided to the sequence controllercircuit 2019. During loss of the external power supply signal VDD, thesequence controller circuit 2019 directs operation of the HV outputlevel shifter circuit 2021 in accordance with a power loss mode definedby the configuration signals C1-C3 (without regard to the input controlsignals A and B).

Operation during loss of the external power supply signal VDD may impactoperations of the various components of the circuit 2001 because of thelimited energy available from the battery. Stated in other words, one ormore of the components of the circuit 2001 may be configured to operatein a low power mode during loss of the signal VDD to extend life of thebattery. For example, the HV output level shifter circuit 2021 may beconfigured to provide low leakage operation, high voltage generationoscillators of the HV generation circuit 2013 may be operated on an“as-needed” basis during loss of the signal VDI), and/or the LED drivercircuit 2027 may be configured to provide a leakage-only mode duringloss of the signal VDD. By reducing current drawn from the battery, aperiod of time can be extended over which the battery can be used duringloss of the signal VDD.

In addition, the battery detect/control circuit 2015 may be configuredto detect a low battery voltage and to indicate the need for areplacement battery, for example, by flashing one or both of the LEDs1023. More particularly, the battery detect/control circuit 2015 mayperiodically sample the battery voltage under a nominal load, and thebattery detect/control circuit 2015 may indicate that a replacementbattery is needed when the battery voltage signal VBat falls toapproximately 2 Volts (to accommodate different battery types). Forexample, the battery detect/control circuit 2015 may sample the batteryvoltage using a nominal load of at least approximately 10 M-ohms.

Logical relationships between inputs and outputs (of electronicsub-assemblies including the circuit 2001 illustrated in FIGS. 41 and42) are provided in Table 1 of FIG. 43. An exponential rise and fall (acapacitor charged and discharged through a transistor) may be sufficientto drive the electrostatically actuated valve chips. Wave shaping (suchas an intentional overshoot and settling voltage), however, may beprovided according to some embodiments of the present invention. InTable 1 of FIG. 43, X denotes a “don't care” condition for therespective signal. Where a “don't care” condition is indicated for oneor both of the input control signals A and/or B, however, the inputcontrol signal may be driven to a high or low voltage at all times.

As shown in Table 1 of FIG. 43, a 5-way, 3-position, cylinder portsexhausted configuration may be provided by providing that theconfiguration signals C1 and C2 are grounded (indicated as 0). Duringnormal operations when the signal VDD is present, the high voltageoutput signals F1-F4 (with 0 indicating valve open and with 1 indicatingvalve closed) and the LED output signals LED-A and LED-B (with 0indicating off and 1 indicating on) may be driven responsive to theinput control signals A and B as indicated. When the configurationsignal C3 is grounded and the signal VDD is interrupted, the HV outputsignals F1-F4 may be driven to the “00” state such that the first andfourth valve chips are opened and the second and third valve chips areclosed (i.e., both cylinder ports are exhausted) without regard to theconditions of the input signals A and B. When the configuration signalC3 is floating (indicated as 1) and the signal VDD is interrupted, theHV output signals F1-F4 may be held in their last state at the time ofthe power interruption without regard to the conditions of the inputsignals A and B.

A 5-way, 3-position, all ports blocked configuration may be provided byproviding that the configuration signal C1 is grounded (indicated as 0)and that the configuration signal C2 is floating (indicated as 1).During normal operations when the signal VDD is present, the highvoltage output signals F1-F4 (with 0 indicating valve open and with 1indicating valve closed) and the LED output signals LED-A and LED-B(with 0 indicating off and 1 indicating on) may be driven responsive tothe input control signals A and B as indicated. When the configurationsignal C3 is grounded and the signal VDD is interrupted, the HV outputsignals F1-F4 may be driven to the “00” state such that all of the valvechips are closed (i.e., both cylinder ports are isolated from highpressure and exhaust ports) without regard to the conditions of theinput signals A and B. When the configuration signal C3 is floating(indicated as 1) and the signal VDD is interrupted, the HV outputsignals F1-F4 may be held in their last state at the time of the powerinterruption without regard to the conditions of the input signals A andB.

A 5-way, 3-position, cylinder ports energized configuration may beprovided by providing that the configuration signal C1 is floating(indicated as 1) and that the configuration signal C2 is grounded(indicated as 0). During normal operations when the signal VDD ispresent, the high voltage output signals F1-F4 (with 0 indicating valveopen and with 1 indicating valve closed) and the LED output signalsLED-A and LED-B (with 0 indicating off and 1 indicating on) may bedriven responsive to the input control signals A and B as indicated.When the configuration signal C3 is grounded and the signal VDD isinterrupted, the HV output signals F1-F4 may be driven to the “00” statesuch that the first and fourth valve chips are closed and the second andthird valve chips are opened (i.e., both actuator ports are energized)without regard to the conditions of the input signals A and B. When theconfiguration signal C3 is floating (indicated as 1) and the signal VDDis interrupted, the HV output signals F1-F4 may be held in their laststate at the time of the power interruption without regard to theconditions of the input signals A and B.

A 5-way, 2-position configuration may be provided by providing that theconfiguration signals C1 and C2 are floating (indicated as 1). Here,only one input control signal B is used, and the input control signal Ais thus in a “don't care” condition. During normal operations when thesignal VDD is present, the high voltage output signals F1-F4 (with 0indicating valve open and with 1 indicating valve closed) and the LEDoutput signals LED-A and LED-B (with 0 indicating off and 1 indicatingon) may be driven responsive to the input control signal B as indicated.When the configuration signal C3 is grounded and the signal VDD isinterrupted, the HV output signals F1-F4 may be driven to the “0” statesuch that the first and third valve chips are opened and the second andfourth valve chips are closed without regard to the conditions of theinput signals A and B. When the configuration signal C3 is floating(indicated as 1) and the signal VDD is interrupted, the HV outputsignals F1-F4 may be held in their last state at the time of the powerinterruption without regard to the conditions of the input signals A andB.

When a voltage is applied to an electrostatically actuated valve chipcontinuously for a sufficient period of time, charge build-up may causedeactivation delays. As applications according to some embodiments ofthe present invention may require that a given state be maintained fordays or even weeks, charge build-up may need to be reduced. Byperiodically reversing the polarity of the applied voltage in thissituation, residual charges can be reduced thereby reducing chargebuild-up and associated actuation delays. Because the valve chip iselectrostatic, the polarity of the applied voltage does not matter.Moreover, if the polarity can be reversed before the valve chip canfully open, physical operation of the device may not be significantlyaffected.

Accordingly, the circuit may be configured to periodically reverse thepolarity of a HV output signal (e.g., F1, F2, F3, and/or F4) applied toa valve chip being held closed for a significant period of time tothereby reduce charge build-up. With an on-chip oscillator used in thehigh voltage generation circuit 2013, a signal can be derived for timingof the polarity switching. An absolute period of the oscillation may notbe critical for any of the functions of the high voltage generationcircuit.

A minimum length of time (t_(rev)) to wait between polarity reversalsmay be determined based on characteristics of the valve chips beingused. Since charge build-up may also occur when the battery is beingused to hold the valve chip states during loss of the external powersupply signal VDD, polarity reversals may also be provided throughoutpower interruptions. Accordingly, polarity reversals may be triggeredwhen the IV generation circuit 2013 is periodically activated duringpower outages so that continuous operation of oscillators of the HVgeneration circuit is not required during power outages. Moreover, ifthe input control signals A and B change state during a polarityreversal operation, the polarity reversal may be completed beforeresponding to the new input control signal command.

When switching from one state to another, product functionality mayrequire that the sequence controller circuit 2019 provide a controlledsequence of deactivations and/or activations during a transition fromone operational state to the next as discussed above, for example, withrespect to FIGS. 4A-F. In other words, a timed sequence of output statesmay be desired after a control input signal changes and/or after a powerstatus changes. Moreover, polarity reversals may include sequencingthrough a series of intermediate states during execution thereof. Moreparticularly, sequencing through intermediate states may provide thatspecific output combinations do not occur for even an instant, and thatcertain intermediate conditions are given sufficient time to settle.

As shown in Table 1 of FIG. 43, there may be 5 unique operational statesof the HV output signals F1-F4 (0101, 1010, 1111, 0110 and 1001) and 14different transition from one operational state to another. Examples ofsequences for all 14 state changes are shown in FIG. 44 according tosome embodiments of the present invention. FIG. 44 also illustratessequences that may be used to execute the 5 polarity reversaltransitions (for each of the five operational states). In addition, aminimum time delay (t_(del)) may be provided before switching to thestates indicated in bold. In addition, the polarity reversal sequencesof FIG. 44 may occur during power loss modes. Accordingly, high voltagesignal transitions may be required using battery power during poweroutages.

A valve chip having its polarity reversed first goes through a statewhere zero volts is applied across it. These points of zero crossingsare indicated with over-line (i.e., “Ō”) in FIG. 44. After the circuit2001 achieves an over-lined state where both HV output signals of a pair(e.g., F1 and F3, or F2 and F4) are driven with zero potentialdifference relative to the respective shared common signal (e.g., HComOor HComE), the polarity of the shared common signal relative to therespective HV output signal pair can be reversed. If the HV outputsignals were initially at a high voltage potential relative to therespective shared common signal at the beginning of the polarityreversal operation, the pair of high voltage output signals and therespective shared common signal may all be pulled to the high voltagepotential during the transition, and then the pair of high voltageoutput signals may be pulled to a low voltage potential relative to therespective shared common signal. If the HV output signals were initiallyat a low voltage potential relative to the respective shared commonsignal at the beginning of the polarity reversal operation, the pair ofhigh voltage output signals and the respective shared common signal mayall be pulled to the low voltage potential during the transition, andthen the pair of high voltage output signals may be pulled to a highvoltage potential relative to the respective shared common signal.

FIGS. 45A-B provide a summary of input/output signals and/or pins of thecircuit 2001. Multiple bond pads may be provided for some of these pinsto accommodate potential current surges.

Electrostatic Discharge (ESD) circuit protection may be provided withinthe circuit 2001 on all input/output pins of the circuit 2001 incompliance with IEC 61000-4-2, Compliance Level 2 (4 kV for contact). Inaddition, the input control signal pins (A and B) and the power supplypins (VDD and GND) may be provided with external Electrical FastTransients (EFT) circuits per IEC 61000-4-4, to Compliance Level 4. Inparticular, a transient voltage suppressor TVS (for example, includingtwo zener diodes) and/or a storage capacitor SC may be provided betweenthe main power supply signal/pin VDD and the ground signal/pin GND. Inaddition, a diode RP1 may be provided between the external power supplyVce and the main power supply signal/pin VDD. In addition, diodes RP2and RP3 may be provided for the input control signals/pins A and B.FIGS. 46A-B provide design parameters for the circuit 2001 according tosome embodiments of the present invention.

A Transient Voltage Suppressor TVS may include a pair of zener diodesconnected between the input power supply signal Vcc/VDD and ground GND.The zener diodes may be placed in series with their cathodes connectedas shown in FIG. 42. The transient voltage suppressor TVS may provideover-voltage protection and may provide protection from relativelylarge, fast transients. The transient voltage suppressor TVS may belocated relatively distant from the circuit 2001 on the printed circuitboard for the electronics sub-assembly to facilitate reliable transientprotection. Volumes, thicknesses, widths, lengths, and materials fortraces of the printed circuit board from the electronics sub-assemblymay be selected to provide effective signal paths for normal operationsand also to provide transient protection at elevated temperatures.

A reverse polarity diode RP1 may also be provided in series with thecircuit 2001 between the power supply pin VDD and the external powersupply Vcc (such as a 24 Volt DC external power supply), and the reversepolarity diode RP1 may provide reverse polarity protection for thecircuit 2001. Additional diodes RP2 and RP3 may provide reverse polarityprotection for input control signals/pins A and B. A storage capacitorSC may be provided in parallel with the transient voltage suppressorTVS, and the storage capacitor SC may provide low pass filtering. Thestorage capacitor SC may also act as a storage device to provide powerto the circuit 2001 during loss of external power. After external power(i.e., Vcc) is lost, the storage capacitor SC may source sufficientelectrical current so that the circuit 2001 may detect the power lossand/or begin transition to a power loss operational mode until thecircuit can switch to the battery 3013.

The high voltage generation circuit 2013 may generate the high voltageHVDD using resistors RL and/or RH and inductors LL and/or LH to createinductive kickback used to charge the storage capacitor HVSC. Theresistors RL and/or RH may be used to limit a maximum kickback voltage,to thereby generate a sufficiently high voltage without damagingswitching circuits of the high voltage generation circuit 2013.

A rate of current change in an inductor is dependent on a voltageapplied across it. A voltage across an inductor can be calculated usingthe equation: V=L(di/dt), and providing a voltage across an inductor maycause the current through the inductor to rise as a ramp. If a switchsourcing/sinking current to/from the inductor is opened, a voltageacross the inductor will rise because the current through the inductorcannot change suddenly due to the inductor property that V=L di/dt. Whenthe switch is opened, the voltage across the inductor will suddenly riseto a level sufficient to force current to flow. By providing theresistors RL and RH in parallel with the inductors LL and LU, a maximumcurrent generated by the inductors can be limited and the possibility ofdamaging the circuit 2001 can be reduced. As shown in FIG. 41, theinductive kickback circuit including inductor LH and resistor RH may beused to charge the high voltage storage capacitor HVSC through thecharging diode CD1. During power outages, the inductive kickback circuitincluding inductor LL and resistor RL may be used to charge the storagecapacitor SC through the charging diode CD2.

FIGS. 47A and 47B are front and back perspective views of a valveassembly including a valve housing 801′, a base 851′, and an-electronicssub-assembly 1001′ according to some embodiments of the presentinvention. In the assembly of FIGS. 47A-B, all couplings to supply,exhaust, and actuator ports may be provided through the base 851′. Asshown, threaded couplings 146 a′ and 146 b′ may provide actuator portsfor a pneumatic cylinder, threaded couplings 142 a′ and 142 b′ mayprovide exhaust ports; and threaded coupling 144 c′ may provide a highpressure supply port. The valve assembly of FIGS. 47A-B may thus providethe same functionalities as discussed above with respect to valveassemblies and components of FIGS. 28-40. Moreover, the electronicssub-assembly 1001′ may be identical to electronic sub-assembliesdiscussed above with respect to FIGS. 33, 35-36, and 39-40.

Moreover, the valve housing 801′ may be identical to the valve housings801 of FIGS. 28-34 and 39-40 with the exception that there are no ports(i.e., banjo fittings 815 a-b or collets 819 a-b) on the surface of thevalve housing 801′ opposite the base 851′. As shown in FIGS. 47A-B asurface of the valve housing 801′ opposite the base 851′ may be flatwith no openings therein. The interior of the valve housing 801′,however, may include chambers, valve enclosures, leads, etc. asdiscussed above with respect to FIGS. 28-34 and 39-40.

The valve housing 801′ of FIGS. 47A-B and the valve housing 801 of FIGS.28-34 and 39-40 may be produced using some shared tooling. Moreparticularly, a same lower molding tool may be used to mold lowerportions of the valve housings 801 and 801′, wherein the same lowermolding tool defines the chambers and valve enclosures of the valvehousings 801 and 801′. Different upper molding tools may be used to molddifferent upper portions of the valve housings 801 and 801′. Moreparticularly, the same lower molding tool may be used together with afirst upper molding tool to mold the valve housing 801 including thebanjo fittings 815 a-b, and the same lower molding tool may be usedtogether with a second upper molding tool to mold the valve housing 801′without openings in the surface of the valve housing 801′ opposite thebase 851′.

As shown in FIG. 48, an extruded aluminum manifold base 851 may providethe same supply port 144 c″ and exhaust ports 144 a-b′ for a pluralityof valve housings 801 a′ to 801 c′ and electronic sub-assemblies 1001 a′to 1001 c′, with the valve housings and electronic sub-assembliesprovided as discussed above with respect to FIGS. 47A-B. Moreover, themanifold base 851″ may provide separate pairs of actuator ports 146 aato 146 af and 146 ba to 146 bf for each valve housing. Fluid couplingmay thus be provided between the supply port 144 c″ and supply chambersof each of the valve housings 801 a′ to 810 c′. Similarly, fluidcoupling may be provided between the exhaust ports 142 a″ and 142 b″ andrespective exhaust chambers of each of the valve housings 801 a′ to 810c′. In contrast, actuator ports 146 aa and 146 ba may be coupled torespective actuator chambers of the valve housing 801 a′; actuator ports146 ab and 146 bb may be coupled to respective actuator chambers of thevalve housing 801 b′; and actuator ports 146 ac and 146 bc may becoupled to respective actuator chambers of the valve housing 801 e′.

Additional actuator ports 146 ad to 146 af and 146 bd to 146 bf may beprovided for additional valve housings coupled to the manifold base851″. The manifold base 851″ illustrated in FIG. 48, for example, isconfigured to accept six valve assemblies. If fewer than six valvehousings are used with the manifold base 851″ of FIG. 48, unused valvehousing positions may be capped to reduce leakage from the supply port144 c″. As shown in FIG. 48, each valve housing position on the manifoldbase 851″ includes couplings 893 to the respective actuator ports and tothe supply and exhaust ports. If a valve housing is not provided at avalve housing position of the manifold base 851″, the couplings 893 (orat least the coupling to the supply port 144″) may be capped to reduceleakage(s). In addition, the manifold base 851″ may be provided with astandard connector such as a connector for a DIN rail 891 (according tothe Deutsche Industrie Norm standard).

The manifold base 851″, for example, may be may be machined from anextruded aluminum profile, and may be mounted on a DIN Rail. The supplyport 144 c″ and the exhaust ports 142 a″ and 142 b″ may be formed byextrusion. The actuator ports 146 aa to 146 af and 146 ba to 146 bf maybe machined into the manifold base 851″ from a direction perpendicularto the supply and exhaust ports. The couplings 893 for the valvehousings to the supply port, the exhaust ports, and the actuator portsmay be machined into the manifold base from a direction perpendicular tothe supply and exhaust ports and perpendicular to the actuator ports.

Valve chips and/or valve assemblies according to embodiments of thepresent invention may also be used in vacuum applications. As shown inFIGS. 49A and 49B, for example, a valve assembly 4141 may define threechambers 4143 a-c separated by two valve chips 4131 a-b supported invalve enclosures of the valve assembly. In addition, a vacuum port 4142may be coupled to a vacuum pump, a relief port 4144 may be coupled to apressure relief source (such as the atmosphere), and the output port4146 may be coupled to a vacuum tool 4148 (such as a vacuum wand used inmicroelectronics fabrication industries to handle microelectronicwafers).

As shown in FIG. 49A, a vacuum may be applied by the vacuum tool 4148 byopening valve flaps of the valve chip 4131 a while closing valve flapsof the valve chip 4131 b so that the output port 4146 is coupled withthe vacuum port 4143 a through valve chip 4131 a. As shown in FIG. 49B,a vacuum may be removed from the vacuum tool 4148 by opening valve flapsof the valve chip 4131 b while closing valve flaps of the valve chip4131 a so that the output port 4146 is coupled with the relief port 4143b through valve chip 4131 b. While not shown in FIGS. 49A-B, the valvechips 4131 a-b may be operated under control of a controller responsiveto user and/or other inputs.

The valve assembly 4141 may be provided, for example, using the valvehousing 801 of FIGS. 28-30 with plugs used to seal valve enclosures 803c-d closed. In an alternative, a three chamber valve assembly may beprovided. Moreover, filters may be provided in one or more of thechambers 4143 a-c to protect the valve chips 4131 a-b. Moreover, thevalve chips 4131 a-b may be packaged as discussed above with respect toFIGS. 6-9 and/or 24-27, and/or baffles may be provided with the valvechips 4131 a-b as discussed above with respect to FIGS. 23-26.

According to some embodiments of the present invention, a valve assemblyand associated controls may be operated using a relatively low powerbattery (such as a battery 513 of FIGS. 15-17, battery 1013 of FIG. 36,and/or battery 3013 of FIG. 42) without an external power supply.Moreover, control signals can be provided via optical communication,radio frequency communication, and/or other wireless communication sothat no electrical connections are required. Such a valve assembly maythus satisfy Intrinsically Safe (1S) requirement standards for ISapplications.

Moreover, microelectromechanical systems (MEMS) valves according to someembodiments of the present invention may operate with lower wear thanconventional mechanical valves. MEMS valves according to someembodiments of the present invention may thus generate fewerparticulates (resulting from wear). Accordingly, MEMS valves accordingto some embodiments of the present invention may be especially useful inapplications that are most sensitive to contamination, such as in thesemiconductor industry, the pharmaceutical industry, the medicalindustry, the biomedical industry, etc.

FIG. 50A is a perspective view of an integrated pneumatic valve andcylinder assembly 5001 according to embodiments of the presentinvention, and FIG. 50B is a cross-sectional view of the assembly 5001of FIG. 50A. Dimensions of elements of FIGS. 50A-B may be exaggeratedfor clarity. More particularly, the assembly may include a cylinder tube5003 (such as a rigid metal cylindrical tube), first and second end caps5005 and 5007, a piston 5008 in the cylinder tube 5003, and a rod 5009coupled to the piston 5008 and extending through the first end cap 5005.In addition, a spring 5010 may be provided in the cylinder tube 5003 topush the piston 5008 and rod 5009 to a retracted (default) position inan unpowered (i.e., an exhausted) state.

As shown in FIG. 50B, the second end cap 5007 may define first, second,and third valve chambers 5015 a-c. The first valve chamber 5015 a may beconfigured to be coupled to a high pressure supply 5011, the secondvalve chamber 5015 b may be configured to be coupled to a cavity 5017within the tube cylinder 5003, and the third valve chamber may beconfigured to be coupled to a low pressure exhaust 5019. In addition,electrostatically actuated valve chips 5021 a-b may be provided in thesecond end cap 5007. More particularly, the valve chip 5021 a may beprovided between the first and second valve chambers 5015 a and 5015 b,and the valve chip 5021 a may be configured to allow fluid communicationfrom the first valve chamber 5015 a to the second valve chamber 5015 bor to block fluid communication between the first and second valvechambers 5015 a and 5015 b responsive to electrical signals appliedthereto. Similarly, the valve chip 5021 b may be provided between thesecond and third valve chambers 5015 b and 5015 c, and the valve chip5021 b may be configured to allow fluid communication from the secondvalve chamber 5015 b to the second third valve chamber 5015 c or toblock fluid communication between the second and third valve chambers5015 b and 5015 c responsive to electrical signals applied thereto.

Electrical signals may be provided to the first and second valve chips5021 a-b via a coupling 5023 to an electrical bus 5025. For example,extend and retract signals may be received at the second end cap 5007from a programmable logic controller (PLC) over the electronic bus 5025and coupling 5023 with a control circuit at the second end cap 5007generating the high voltage signals and/or providing logic forsequencing, power loss operations, polarity reversal, etc. In analternative, some or all processing of extend and retract signals mayoccur outside the second end cap 5007.

Accordingly, the valve chips 5021 a-b may provide 3-way valvefunctionality to control extension and retraction of the piston 5008 androd 5009. In a first condition, the valve chip 5021 a may be closed tosubstantially block fluid communication between the first and secondvalve chambers 5015 a-b, and the second valve chip 5021 b may be openedto allow fluid communication between the second and third valve chambers5015 b-c. Accordingly, the cavity 5017 may be coupled through the secondvalve chip 5021 b to the low pressure exhaust 5019 so that the spring5010 pushes the piston 5008 and rod 5009 to the retracted position.

In a second condition, the valve chip 5021 a may be opened to allowfluid communication between the first and second valve chambers 5015a-b, and the second valve chip 5021 b may be closed to substantiallyblock fluid communication between the second and third valve chambers5015 b-c. Accordingly, the cavity 5017 may be coupled through the firstvalve chip 5021 a to the high pressure supply 5019 so that the piston5008 and rod 5009 are pushed to the extended position therebycompressing the spring 5010.

Five-way valve functionality may be provided, for example, by similarlyincluding two valve chips in the first end cap 5005 to thereby control acoupling of supply and exhaust pressures to a second cavity of thecylinder tube 5003 between the piston 5008 and the first end cap 5005.Accordingly, electrical and pressure couplings may be provided at bothend caps. In an alternative, 5-way operations may be provided using fourvalve chips provided at one of the end caps with a pneumatic coupling(s)provided between the two end caps. With five-way valve operations, thespring 5010 may not be required.

The end caps 5005 and 5007 and the cylinder tube 5003 may be formedseparately and then assembled. Ends of the cylinder tube 5003, forexample, may be threaded to receive female threads of the respective endcaps 5005 and 5007, or the tube and end caps may be assembled by othermeans known to those having skill in the art.

The valve chips 5021 a-b may be provided and/or packaged as discussedabove with respect to FIGS. 1-2, 5-9, and/or 24-27, and the end cap 5007may be formed of a rigid material by molding, turning (e.g., on alathe), machining and/or other means known to those having skill in theart. After forming the end cap 5007 including the valve chambers 5015a-c, the valve chips can be inserted into an opening(s) in the end cap5007, and a base can be secured to the opening(s) in the end cap 5007before securing the end cap 5007 (with the valve chips and base) to thecylinder tube 5008. The end cap 5007 may thus provide a rigid valvehousing, the first and second valves 5015 a-b may be provided in therigid valve housing defined by the end cap 5007, and the rigid valvehousing defined by the end cap 5007 may be mounted directly to thecylinder tube 5003. Accordingly, a fluid seal may be provided betweenthe valve housing defined by the end cap 5007 and the cylinder tube5003.

While embodiments of the present invention have been discussed abovewith valve assemblies used to control pneumatic actuators includingrods, valve assemblies according to embodiments of the present inventioncan also be used to control pneumatic actuators including rodlesscylinders such as magnetically coupled cylinders and/or rotaryactuators. For example, the rod 5009 may be eliminated from thestructure of FIGS. 50A-B, and a magnet may be coupled to the piston 5008inside the cylinder tube 5003. Accordingly, movement of the magnet withthe piston 5008 inside the cylinder tube 5003 may be used to affectmovement of a carriage outside the cylinder tube 5003.

While the present invention has been particularly shown and describedwith reference to embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

1.-23. (canceled)
 24. A method of packaging a valve chip including asubstrate having first and second faces and a hole through the substratebetween the first and second faces, a moveable valve member on one ofthe faces of the substrate with the moveable valve member beingassociated with the hole, the method comprising: forming a frame havingan opening therein; and securing the valve chip in the opening of theframe so that central portions of the first and second faces of thesubstrate are exposed through the opening in the frame and so that afluid seal is provided between the frame and edges of the substrate. 25.A method according to claim 24 wherein the moveable valve membercomprises a flexible valve flap.
 26. A method according to claim 24wherein forming the frame comprises molding the frame separate from thevalve chip, and wherein securing the valve chip comprises securing thevalve chip in the opening of the frame after completion of molding. 27.A method according to claim 24 wherein the valve chip includes a pair ofinput pads on the substrate, and wherein providing the frame includesproviding first and second conductive leads in the frame, the methodfurther comprising: after securing the valve chip in the opening,electrically coupling the first and second conductive leads to therespective input pads on the substrate.
 28. A method according to claim27 wherein portions of the first and second conductive leads are exposedalong an outside edge of the frame.
 29. A method according to claim 28wherein the exposed portions of the first and second conductive leadsare oriented in a direction substantially perpendicular with respect tothe substrate.
 30. A method according to claim 28 wherein the exposedportions of the first and second conductive leads are exposed throughslots in the frame.
 31. A method according to claim 27 whereinelectrically coupling the first and second conductive leads compriseswire bonding the first and second conductive leads to the respectiveinput pads.
 32. A method according to claim 24 wherein the frame has athickness greater than a thickness of the substrate and wherein theframe includes a recessed ledge along the opening therein with the edgesof the substrate being supported by the recessed ledge.
 33. A methodaccording to claim 32 further comprising: before securing the valve chipin the opening, forming a flexible gasket on the recessed ledge whereinsecuring the valve chip comprises securing edges of the substrate on theflexible gasket.
 34. A method according to claim 33 wherein forming theframe and forming the flexible gasket comprise molding the frame and thegasket using a first shot of a first material for the frame and a secondshot of a second material for the gasket.
 35. A method according toclaim 32 wherein securing the valve chip includes placing the valve chipon the recessed ledge and then deforming portions of the frame tooverlap edges of the substrate opposite the recessed ledge so that edgesof the substrate are secured between the recessed ledge and the deformedportions of the frame.
 36. A method according to claim 32 whereinsecuring the valve chip includes providing an adhesive between the edgesof the substrate and the recessed ledge.
 37. A method according to claim24 further comprising: providing a baffle on the frame wherein thebaffle is spaced apart from the substrate and wherein the baffle has atleast one opening there through.
 38. A method according to claim 37wherein the baffle provides a restriction to fluid flow in series withthe plurality of holes through the substrate.
 39. A method according toclaim 37 wherein the baffle has a wedge shape.
 40. A method according toclaim 39 wherein the frame includes first and second conductive leads ona first edge of the frame, the first and second conductive leads beingelectrically coupled to the respective input pads on the substrate,wherein a thin portion of the baffle is adjacent the first edge of theframe and wherein a wide portion of the baffle is adjacent a second edgeof the frame opposite the first edge.
 41. A method according to claim 37wherein the baffle, the frame, and the substrate define an enclosurewith the moveable valve member being included in the enclosure.
 42. Amethod according to claim 37 further comprising: forming a flexiblegasket on the frame such that the frame is between the flexible gasketand the baffle.
 43. A method according to claim 24 further comprising:before securing the valve chip in the opening, forming a flexible gasketon the frame, the flexible gasket defining an opening therein havingdimensions greater than dimensions defined by a perimeter of thesubstrate.
 44. A method according to claim 43 wherein forming the frameand forming the flexible gasket comprise molding the frame and thegasket using a first shot of a first material for the frame and a secondshot of a second material for the gasket.
 45. A method according toclaim 24 wherein the frame comprises a rigid polymer material.
 46. Amethod according to claim 24 further comprising: providing a housingdefining first and second chambers and a valve chip enclosure betweenthe first and second chambers, wherein the first and second chambers andthe valve chip enclosure are open at one end; after securing the valvechip in the opening of the frame, inserting the frame in the valve chipenclosure; and after inserting the frame in the valve chip enclosure,securing a base on the open end of the housing so that the first andsecond chambers are separated by the valve chip.
 47. A method accordingto claim 46 wherein the housing includes a first port providing fluidcommunication into and/or out of the first chamber and wherein the baseincludes a second port providing fluid communication into and/or out ofthe second chamber. 48.-112. (canceled)